we have replaced a mailing list with about 500 participants with XenForo. The mailing list was moderated, i.e. moderated reviewed new posts and approved them, sending them out to the participants.
To keep the transition for the participants as smooth as possible, we keep new posts moderated until the moderator approves them. We have set all members to receive email notification on new threads/posts.
This works fine, but when two posts are approved within 10 minutes, we hit a limit with the mail server of our domain. We changed (first suggestion from support) the SMTP port to 587, but this did not cure the problem.
When we had this problem again today, we contacted the support again and received the statement "according to our logfiles you are hitting the limits for SMTP regarding the maximum number of mails to be sent within 10 minutes.
Either send your mails more slowly, or use sendmail / php-mail functions."
Any way to do this?