I searched but could not find an answer. I just started RoundCube for my new site's webmail today and I am getting a 20-minute delay when I choose HTML as the format for my email. If I choose plain text, my email goes through immediately. If I choose HTML (I want to include links) then my original email or my reply doesn't get to the recipient for exactly 20 minutes. That doesn't seem normal. Any suggestions?
Does anyone else have this problem, or do HTML messages go through immediately for you?
I have ~2500 users, at least half using HTML exclusively. No delays for us.
I have seen similar "fixed" delay time before with some mail servers, can't say what the cause was since there weren't my mail servers.
Enable smtp_debug in Roundcube to see where it "hangs" on Roundcube side or the SMTP server.