Mails.so Webflow Integration
🌎Mails.so is an API service for email validation and verification. It helps you keep your contact lists clean, accurate, and free from invalid or risky addresses.
Mails.so is a developer-friendly email verification API that validates addresses with precision and speed. When integrated with your Webflow site, Mails.so ensures that every email collected through forms, pop-ups, and landing pages is genuine and deliverable — protecting your sending reputation and maximizing the ROI of your email marketing efforts.
The integration operates through Mails.so's REST API, which you can connect to Webflow via automation platforms like Zapier or Make, or through a custom middleware layer. Each Webflow form submission triggers a verification call — Mails.so checks the address for proper syntax, valid domain configuration, active mailbox status, and risk signals like disposable domains or catch-all servers. The results route the submission: valid addresses proceed to your CRM, while invalid ones are discarded or flagged for review.
Mails.so also supports bulk verification for existing lists, which is valuable for Webflow sites that have accumulated contacts over months or years. Export your Webflow CMS contacts, run them through Mails.so's bulk endpoint, and receive detailed verification reports categorized by result type. Re-import only verified addresses to instantly improve deliverability metrics and reduce wasted email sends. For developers building custom Webflow integrations, Mails.so's clean API design and comprehensive documentation make implementation straightforward.
Recent builds that deliver
Clients I've helped ship better Webflow sites
"As I grow in my business, I need services to grow with, Derrick is that service when it comes to my website. He is patient, listens and takes onboard the changes I want in a timely manner. My website changes and develops with the needs of my clients and my offer which is great. He also brings new ideas and perspectives in how to improve and grow in line with my goals and business needs. I look forward seeing how this new phase develops."
Karin Young
Psychotherapist · Karin Counselling
"Derrick has been a great help in getting our SaaS website up and running. He is very knowledgeable in Webflow and was able to help us get the most out of the platform. His design skills are excellent and he was able to create a custom function-filled website that looks great and operates perfectly. I would highly recommend Derrick to anyone looking for a web designer who knows his stuff!"
Taita Ngetich
CEO · Synnefa
"Derrick is just great to work with! He's super fast, always responds in a timely manner, and is very flexible with last-minute requests. His Webflow development skills are rock solid and he has no problems keeping up with the fast pace of early-stage startups."
Carla Nassisi
Growth · Briink
"It has been a pleasure to work with Derrick! He delivered a pixel-perfect website for LLI, which not only looks and performs well but is also very organised and simple to maintain! During the process, he had the patience to clear all the incoming doubts that occurred when we were transitioning from one platform to another, and he not only delivered a great site but also tutorials on how to manage it."
Isabelle Krauze
UX Lead · LLInformatics
"Derrick is a gem of a person and a wealth of knowledge. He was so patient and helpful when explaining the more intricate parts of Webflow and bouncing around different possible solutions. He really knows the ins and outs of Webflow — it's no wonder that he's a certified Webflow Expert! I'm looking forward to the day when I get to work with him again."
Diana Donaldson
CEO · Be Indigo
"Derrick helped us redesign and build our site on Webflow and we couldn't be more pleased with the entire project. Derrick is very easy to communicate with, fast and efficient, and takes time to ask questions and provide suggestions where necessary. He has a great balance of technical and visual knowledge, which helped us build a fast, SEO-optimized site that looks great and is on-brand. Would happily hire Derrick again!"
Eliza Gerland
Strategic Marketer · UFODrive
"Derrick and his team were wonderful to work with and helped us a lot with launching multiple Webflow projects in addition to doing a full website backend revamp. Recommend him to anyone!"
Liza Moiseeva
CMO · Commons
"Derrick and his colleague were tasked with helping to implement new designs for our Home and Product pages on our website. We had a super tight deadline and they took it in their stride. Their communication throughout the project was great and the results were fantastic. Would highly recommend."
Marcus Vitelli
Brand Executive · Flexciton
"Derrick translated our ideas into visually stunning designs. He took our vision for Mirador Local's online presence and brought it to life in a way that exceeded our expectations. I highly recommend him to anyone seeking a talented and reliable designer for their next project."
Gerry White
Global Growth · Mirador
"Derrick has a solid and broad understanding of Webflow and has delivered huge improvements to our website."
Tim Sater
Marketing Lead · Provenance
"Derrick and his team did a great job building our marketing site and leaving us with the tools to sustainably iterate on our website. They didn't stop until the site perfectly matched our design vision. We would definitely work with them again!"
John Outwater
Data Visualization · Renoster
"Derrick made our vision a reality, he's simply a brilliant website developer. We're incredibly happy with the results, which match the designs. If you're a startup or scale-up looking for an excellent web developer to turn your ideas into reality, look no further!!"
Ben Leftley
Senior Delivery Manager · Unmind
"It was great working with Derrick’s team! Communication was smooth and the website ideation, design and development were executed well without much hiccups. Will highly recommend for your website projects! :)"
Indra Basak
Marketing · PreciX
"Derrick was conscientious, efficient and delivered on time. Communication was effective and they really understood the issues at hand. He ultimately delivered a professional looking website that exceeded expectations."
Miles Owen
Head of Digital · FMpay
"As I grow in my business, I need services to grow with, Derrick is that service when it comes to my website. He is patient, listens and takes onboard the changes I want in a timely manner. My website changes and develops with the needs of my clients and my offer which is great. He also brings new ideas and perspectives in how to improve and grow in line with my goals and business needs. I look forward seeing how this new phase develops."
Karin Young
Psychotherapist · Karin Counselling
"Derrick has been a great help in getting our SaaS website up and running. He is very knowledgeable in Webflow and was able to help us get the most out of the platform. His design skills are excellent and he was able to create a custom function-filled website that looks great and operates perfectly. I would highly recommend Derrick to anyone looking for a web designer who knows his stuff!"
Taita Ngetich
CEO · Synnefa
"Derrick is just great to work with! He's super fast, always responds in a timely manner, and is very flexible with last-minute requests. His Webflow development skills are rock solid and he has no problems keeping up with the fast pace of early-stage startups."
Carla Nassisi
Growth · Briink
"It has been a pleasure to work with Derrick! He delivered a pixel-perfect website for LLI, which not only looks and performs well but is also very organised and simple to maintain! During the process, he had the patience to clear all the incoming doubts that occurred when we were transitioning from one platform to another, and he not only delivered a great site but also tutorials on how to manage it."
Isabelle Krauze
UX Lead · LLInformatics
"Derrick is a gem of a person and a wealth of knowledge. He was so patient and helpful when explaining the more intricate parts of Webflow and bouncing around different possible solutions. He really knows the ins and outs of Webflow — it's no wonder that he's a certified Webflow Expert! I'm looking forward to the day when I get to work with him again."
Diana Donaldson
CEO · Be Indigo
"Derrick helped us redesign and build our site on Webflow and we couldn't be more pleased with the entire project. Derrick is very easy to communicate with, fast and efficient, and takes time to ask questions and provide suggestions where necessary. He has a great balance of technical and visual knowledge, which helped us build a fast, SEO-optimized site that looks great and is on-brand. Would happily hire Derrick again!"
Eliza Gerland
Strategic Marketer · UFODrive
"Derrick and his team were wonderful to work with and helped us a lot with launching multiple Webflow projects in addition to doing a full website backend revamp. Recommend him to anyone!"
Liza Moiseeva
CMO · Commons
"Derrick and his colleague were tasked with helping to implement new designs for our Home and Product pages on our website. We had a super tight deadline and they took it in their stride. Their communication throughout the project was great and the results were fantastic. Would highly recommend."
Marcus Vitelli
Brand Executive · Flexciton
"Derrick translated our ideas into visually stunning designs. He took our vision for Mirador Local's online presence and brought it to life in a way that exceeded our expectations. I highly recommend him to anyone seeking a talented and reliable designer for their next project."
Gerry White
Global Growth · Mirador
"Derrick has a solid and broad understanding of Webflow and has delivered huge improvements to our website."
Tim Sater
Marketing Lead · Provenance
"Derrick and his team did a great job building our marketing site and leaving us with the tools to sustainably iterate on our website. They didn't stop until the site perfectly matched our design vision. We would definitely work with them again!"
John Outwater
Data Visualization · Renoster
"Derrick made our vision a reality, he's simply a brilliant website developer. We're incredibly happy with the results, which match the designs. If you're a startup or scale-up looking for an excellent web developer to turn your ideas into reality, look no further!!"
Ben Leftley
Senior Delivery Manager · Unmind
"It was great working with Derrick’s team! Communication was smooth and the website ideation, design and development were executed well without much hiccups. Will highly recommend for your website projects! :)"
Indra Basak
Marketing · PreciX
"Derrick was conscientious, efficient and delivered on time. Communication was effective and they really understood the issues at hand. He ultimately delivered a professional looking website that exceeded expectations."
Miles Owen
Head of Digital · FMpay
"As I grow in my business, I need services to grow with, Derrick is that service when it comes to my website. He is patient, listens and takes onboard the changes I want in a timely manner. My website changes and develops with the needs of my clients and my offer which is great. He also brings new ideas and perspectives in how to improve and grow in line with my goals and business needs. I look forward seeing how this new phase develops."
Karin Young
Psychotherapist · Karin Counselling
"Derrick has been a great help in getting our SaaS website up and running. He is very knowledgeable in Webflow and was able to help us get the most out of the platform. His design skills are excellent and he was able to create a custom function-filled website that looks great and operates perfectly. I would highly recommend Derrick to anyone looking for a web designer who knows his stuff!"
Taita Ngetich
CEO · Synnefa
"Derrick is just great to work with! He's super fast, always responds in a timely manner, and is very flexible with last-minute requests. His Webflow development skills are rock solid and he has no problems keeping up with the fast pace of early-stage startups."
Carla Nassisi
Growth · Briink
"It has been a pleasure to work with Derrick! He delivered a pixel-perfect website for LLI, which not only looks and performs well but is also very organised and simple to maintain! During the process, he had the patience to clear all the incoming doubts that occurred when we were transitioning from one platform to another, and he not only delivered a great site but also tutorials on how to manage it."
Isabelle Krauze
UX Lead · LLInformatics
"Derrick is a gem of a person and a wealth of knowledge. He was so patient and helpful when explaining the more intricate parts of Webflow and bouncing around different possible solutions. He really knows the ins and outs of Webflow — it's no wonder that he's a certified Webflow Expert! I'm looking forward to the day when I get to work with him again."
Diana Donaldson
CEO · Be Indigo
"Derrick helped us redesign and build our site on Webflow and we couldn't be more pleased with the entire project. Derrick is very easy to communicate with, fast and efficient, and takes time to ask questions and provide suggestions where necessary. He has a great balance of technical and visual knowledge, which helped us build a fast, SEO-optimized site that looks great and is on-brand. Would happily hire Derrick again!"
Eliza Gerland
Strategic Marketer · UFODrive
"Derrick and his team were wonderful to work with and helped us a lot with launching multiple Webflow projects in addition to doing a full website backend revamp. Recommend him to anyone!"
Liza Moiseeva
CMO · Commons
"Derrick and his colleague were tasked with helping to implement new designs for our Home and Product pages on our website. We had a super tight deadline and they took it in their stride. Their communication throughout the project was great and the results were fantastic. Would highly recommend."
Marcus Vitelli
Brand Executive · Flexciton
"Derrick translated our ideas into visually stunning designs. He took our vision for Mirador Local's online presence and brought it to life in a way that exceeded our expectations. I highly recommend him to anyone seeking a talented and reliable designer for their next project."
Gerry White
Global Growth · Mirador
"Derrick has a solid and broad understanding of Webflow and has delivered huge improvements to our website."
Tim Sater
Marketing Lead · Provenance
"Derrick and his team did a great job building our marketing site and leaving us with the tools to sustainably iterate on our website. They didn't stop until the site perfectly matched our design vision. We would definitely work with them again!"
John Outwater
Data Visualization · Renoster
"Derrick made our vision a reality, he's simply a brilliant website developer. We're incredibly happy with the results, which match the designs. If you're a startup or scale-up looking for an excellent web developer to turn your ideas into reality, look no further!!"
Ben Leftley
Senior Delivery Manager · Unmind
"It was great working with Derrick’s team! Communication was smooth and the website ideation, design and development were executed well without much hiccups. Will highly recommend for your website projects! :)"
Indra Basak
Marketing · PreciX
"Derrick was conscientious, efficient and delivered on time. Communication was effective and they really understood the issues at hand. He ultimately delivered a professional looking website that exceeded expectations."
Miles Owen
Head of Digital · FMpay
"As I grow in my business, I need services to grow with, Derrick is that service when it comes to my website. He is patient, listens and takes onboard the changes I want in a timely manner. My website changes and develops with the needs of my clients and my offer which is great. He also brings new ideas and perspectives in how to improve and grow in line with my goals and business needs. I look forward seeing how this new phase develops."
Karin Young
Psychotherapist · Karin Counselling
"Derrick has been a great help in getting our SaaS website up and running. He is very knowledgeable in Webflow and was able to help us get the most out of the platform. His design skills are excellent and he was able to create a custom function-filled website that looks great and operates perfectly. I would highly recommend Derrick to anyone looking for a web designer who knows his stuff!"
Taita Ngetich
CEO · Synnefa
"Derrick is just great to work with! He's super fast, always responds in a timely manner, and is very flexible with last-minute requests. His Webflow development skills are rock solid and he has no problems keeping up with the fast pace of early-stage startups."
Carla Nassisi
Growth · Briink
"It has been a pleasure to work with Derrick! He delivered a pixel-perfect website for LLI, which not only looks and performs well but is also very organised and simple to maintain! During the process, he had the patience to clear all the incoming doubts that occurred when we were transitioning from one platform to another, and he not only delivered a great site but also tutorials on how to manage it."
Isabelle Krauze
UX Lead · LLInformatics
"Derrick is a gem of a person and a wealth of knowledge. He was so patient and helpful when explaining the more intricate parts of Webflow and bouncing around different possible solutions. He really knows the ins and outs of Webflow — it's no wonder that he's a certified Webflow Expert! I'm looking forward to the day when I get to work with him again."
Diana Donaldson
CEO · Be Indigo
"Derrick helped us redesign and build our site on Webflow and we couldn't be more pleased with the entire project. Derrick is very easy to communicate with, fast and efficient, and takes time to ask questions and provide suggestions where necessary. He has a great balance of technical and visual knowledge, which helped us build a fast, SEO-optimized site that looks great and is on-brand. Would happily hire Derrick again!"
Eliza Gerland
Strategic Marketer · UFODrive
"Derrick and his team were wonderful to work with and helped us a lot with launching multiple Webflow projects in addition to doing a full website backend revamp. Recommend him to anyone!"
Liza Moiseeva
CMO · Commons
"Derrick and his colleague were tasked with helping to implement new designs for our Home and Product pages on our website. We had a super tight deadline and they took it in their stride. Their communication throughout the project was great and the results were fantastic. Would highly recommend."
Marcus Vitelli
Brand Executive · Flexciton
"Derrick translated our ideas into visually stunning designs. He took our vision for Mirador Local's online presence and brought it to life in a way that exceeded our expectations. I highly recommend him to anyone seeking a talented and reliable designer for their next project."
Gerry White
Global Growth · Mirador
"Derrick has a solid and broad understanding of Webflow and has delivered huge improvements to our website."
Tim Sater
Marketing Lead · Provenance
"Derrick and his team did a great job building our marketing site and leaving us with the tools to sustainably iterate on our website. They didn't stop until the site perfectly matched our design vision. We would definitely work with them again!"
John Outwater
Data Visualization · Renoster
"Derrick made our vision a reality, he's simply a brilliant website developer. We're incredibly happy with the results, which match the designs. If you're a startup or scale-up looking for an excellent web developer to turn your ideas into reality, look no further!!"
Ben Leftley
Senior Delivery Manager · Unmind
"It was great working with Derrick’s team! Communication was smooth and the website ideation, design and development were executed well without much hiccups. Will highly recommend for your website projects! :)"
Indra Basak
Marketing · PreciX
"Derrick was conscientious, efficient and delivered on time. Communication was effective and they really understood the issues at hand. He ultimately delivered a professional looking website that exceeded expectations."
Miles Owen
Head of Digital · FMpay
Mails.so FAQs
Common questions about using Mails.so with Webflow.
The most practical approach is through an automation platform like Zapier or Make. Create a workflow where a Webflow form submission acts as the trigger, then add a Mails.so API verification step. Based on the result, you can branch the workflow: send valid emails to your CRM, discard invalid ones, and flag risky addresses for manual review. Direct API integration is also possible with a lightweight serverless function.
Mails.so runs multiple checks including syntax validation, domain MX record verification, SMTP handshake testing to confirm the mailbox exists, and detection of disposable email services, role-based addresses, and known spam traps. Each check produces a discrete result code so you can apply granular handling rules — for example, accepting valid and catch-all results while rejecting disposable and invalid results.
Yes, export your contacts from Webflow CMS as a CSV file and upload it to Mails.so's bulk verification endpoint. The service processes the list and returns a detailed report showing the verification status of each address. You can then filter out problematic addresses and re-import only the clean records. Bulk verification is a recommended quarterly practice for any Webflow site that regularly collects emails.
Minimal — Mails.so's API responds in 100-300ms on average, and verification happens asynchronously after the form is submitted. The visitor sees an immediate confirmation page while the backend automation handles verification and routing. This ensures your form experience remains fast and frictionless regardless of the verification processing behind the scenes.
Mails.so offers pay-as-you-go pricing with per-verification credits, making it affordable for sites of any size. There is no monthly subscription requirement, and unused credits roll forward. A free tier is available for testing, and the paid plans scale linearly with your verification volume. For most Webflow sites, the entry-level credit pack provides months of real-time form verification.
Need Mails.so on your Webflow site?
I integrate tools like this for clients all the time. Talk to me about your setup.