You can use SMTP [1] if you need something like that . While SMTP technically slower than REST, practically it doesn't matter if your application processes mail

You can use SMTP [1] if you need something like that . While SMTP technically slower than REST, practically it doesn't matter if your application processes mailjobs in forked background threads or a queue, also most ESPs would rate limit outgoing email after it reaches their system to prevent abuse. the benefit is also no custom code or needing to add their SDK, you can replace the service by simply replacing the credentials, probably without even a code deployment if you store credentials in env. [1] https://help.mailgun.com/hc/en-us/articles/203409084-How-do-I-create-additional-SMTP-credentials- https://help.mailgun.com/hc/en-us/articles/203409084-How-do-...