I am planning to switch from transactional mail service providers (Mailgun, Mailjet, etc.) to self hosted Mailcow due to recommendations from fellow admins.
My use case is transactional email, specifically, sending out registration confirmation emails and welcoming users. Essentially, I only need a single mailbox (no-reply@) and will use Mailcow solely as SMTP server.
The first attempt wasn’t successful. Google had a high bounce rate due to “misconfigured” SPF records. I wasn’t able to resolve the issue so had to switch back to a commercial offering for now.
I hope I can clarify some of my questions with the help of the community.
Here is the setup:
- Website is at home.social with IP a.a.a.a
- Mailcow is at smtp.home.social with IP b.b.b.b
- MX records for home.social point to Gmail as I don’t plan to use Mailcow for receiving emails
- The application at a.a.a.a uses Mailcow at b.b.b.b to send out user notifications as no-reply@home.social
I had DKIM in place and validated. The SPF record was as follows:
v=spf1 ip4:b.b.b.b mx a -all
for the mail domain, ie. home.social.
However, Google bounced >50% of the traffic.
What am I doing wrong? Should it probably be ~all
versus -all?
If so, why? Should I remove the mx a
?
Any help is greatly appreciated. And sorry if these are sort of beginner level questions.