What I did in the end was point the RoundCube installation on my old server to use my new new server, and it had the same problem. Since I knew the old environment worked it basically pointed the finger at the mail server. I then logged on using mail2web.com to confirm which also had the same issue. Once I had narrowed the problem to the mail server environment on the new box, then it was pretty easy to track down that the message table in the mail server database was not correct.
I'd suggest you try and use something like mail2web.com just to test you domain. If mail2web.com doesn't work either, then it is likely to be mail server. If it does work then it could well be your RC config. Be sure to turn on logging in RC so you can get an idea of what is going on.
Hello Ryan,
Could you explain a bit how you identified the fact that the database and the mailstore got out of sync?. I seem to have a similar problem for a few days now. I have been using RC for the past few months. Hosted shared server, no control. All of a sudden, many users cannot send mails. Screen coming back "Failed to send message". RC reinstalled on another test domain works well, so my best guess is database corruption.
Thanks in advance
kmn
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