Have you tried sending mail to another server/mail provider to see if yahoodns doesn't block you? It oculd be possible they block dialup / dsl /.... home user internet connections since they are usually a source of spam.
OK ... That figures, I personally do not enjoy Yahoo services. Well then moving to next stone in the path. Will try using Thunderbird to send / receive from the account. CB
OK... well now the email is working from Thunderbird (remote computer) to server. Roundcube displays incoming messages and received messages. Still does not send / reply to anything. Simply does nothing when send or reply is clicked, screen stays "static" with no observable changes. System mail for "root" access shows mail received at system level, my normal login does not. IE I have to sudo -s into root to see message traffic. If I have not thanked you before - I will now. You have been most helpful with this thread. Do we have a "kudos" type of system here? CB
Is there anything helpful in /var/log/mail.info when trying to send mail from roundcube? Did you use your Thunderbird test to send mail from external mail account to your server or using your server to send to external account? That would be interesting if both works from there. If it does, there could be an issue with roundcube or local mail injection.
Checked for /var/log/mail.info - file not found. Yes - I used T-bird email from my Frontier Account at a remote computer not attached to the same LAN as my server. I can send / receive emails from my Frontier email to by Handyman-it email on that remote computer, using Thunderbird. Just applied several updates to system and rebooting server. Will check to see if Roundcube still fails to work after restart. CB
Roundcube now fails to send or reply and exits with error stating: REQUEST CHECK FAILED Access to this service was denied due to failing security checks! Please contact your server-administrator. It does nothing other than display that message.
Frontier Communications (my ISP) is blocking port 25 (inbound) to MTA according to their advanced tech support people. I do not see that when I port scan my server - hmmm. They just changed my IP address again - now I am really going to go off on them (grin) - it was supposedly a static IP lease. CB
The Request check failed message has been a bug in roundcube when using check_referer=true https://github.com/roundcube/roundcubemail/commit/4571305398832109bae57be87961f68a38bf7d05