I have a Linux VPS with two Drupal sites, one of them using Drupal Commons. Both installations are told to send mail via sendmail, which in turn is configured to relay mail to the Gmail SMTP server (via the smart host directive). Two different accounts, on two different (free) Google Apps domains are used to send.
The non-Commons server is used to send out a newsletter to a large-for-me number of recipients (>350), yet I've never had a problem with this account being suspended. The Commons server is set up with notification rules to send emails to everyone subscribing to a certain piece of content, or a group, or a user, etc. However, the bulk of these notifications are much smaller, perhaps 20-30 in a batch, and the site is not heavily trafficked. Yet Google keeps suspending my user on that domain "for abuse" every few days.
Has anyone run into something similar, and hopefully found a workaround for it? I have ensured I've set SPF and DKIM records on (both) my hosts at this point but it hasn't seemed to help.
Any other suggested methods I might be able to send out mail from my two domains without going through Google's SMTP service? In the case of the Commons site, it is just a notifier and I do not need to accept return emails.
Grateful for any assistance, and happy to post any of my configs (just not sure which configs would be most suitable).