Don’t most of these services explicitly disallow using them for newsletter type of use? If you send a bunch of the same types of emails to bursts of thousands of users at once, those companies have algorithms that will eventually pick it up (especially if there are lots of images/content embedded).
Am I misunderstanding the limitations of which services are available to use for “bring your own SMTP”?
Good point! You're absolutely right that many basic SMTP providers (Gmail, Outlook, etc.) restrict bulk newsletter sending to large number of emails.
Fertit is designed to work with newsletter-appropriate SMTP services like SendGrid, Mailgun, Amazon SES, Postmark, and Mailjet - providers that explicitly
support bulk email sending. These typically cost $10-50/month depending on volume, which is still much cheaper than the $79+ full-service ESPs charge.
The value prop is: instead of paying ConvertKit $79/month for 1000 subscribers, you pay SendGrid ~$15/month for SMTP + Fertit $9.99/month = ~$25/month total, while still getting proper unsubscribe handling, preference management, and basic compliance features.
You're right that it requires users to handle the SMTP setup themselves - it's positioned for people who want more control and cost savings but don't need the full white-glove deliverability management of premium ESPs.
Thanks for pointing this out - I should make the SMTP requirements clearer in the marketing!
If you look at Postmarks website, they explicitly disallow the service you are promoting. Marketing emails are not allowed to be sent through Postmark.
Am I misunderstanding the limitations of which services are available to use for “bring your own SMTP”?