I have been using MiaB for years and love it as many of you already know from my participation here in the Discourse Forum for Mail-in-a-Box.
One of the biggest headaches of ‘self-hosting’ email is deliver-ability. I have been blessed that my major installs have not had any issues over the years, but when they do occur they can be maddening.
At this time, one of my servers is having issues with deliver-ability to Gmail … but not the usual, “My email went to spam” but instead delivery is hit and miss with 2 specific accounts (so far). I will get a bounce from Gmail immediately saying that my message was blocked as it likely unsolicited email. The messages in question are REPLIES being sent to their users.
A sample header looks like this: (potential personal info redacted)
<firstname.lastname@example.org>: host gmail-smtp-in.l.google.com[220.127.116.11] said: 550-5.7.1 [111.222.333.444 12] Our system has detected that this message is 550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent to Gmail, 550-5.7.1 this message has been blocked. Please visit 550-5.7.1 https://support.google.com/mail/?p=UnsolicitedMessageError 550 5.7.1 for more information. a02rc2840453wmh.112 - gsmtp (in reply to end of DATA command)
The maddening aspect of this is when I contact the correspondent via another email account, sometimes they say, “Oh I got this email from you” … meaning that it was not ever even blocked to begin with!!! WTH!!! But that is hit and miss, so the end result is that I do not know if this server’s outbound email to Gmail is being delivered, or not.
So in that end … I have to ask the community which SMTP services you have used and how have they worked for you? I am most interested in free services, as this host’s outbound email is in the single digits daily. Can anyone offer real world cases? Thanks in advance for any and all replies!