Outgoing mail times out when whitelist is enabled

[centralusa]

We have a very large white list enabled on our server and have been having issues sending mail and I was able to narrow down the source of the issue and it was the whitelist (it probably has over 500 domains in it). As soon as I disabled it mail was able to go out from smtp authenticated clients without issue. When it was enabled sendign mail from Outlook would just sit in the outbox forever and then timeout and never get sent. Any tips on what I may be doing to cause this behavior?

[Code Crafters]

SPAM filtering is done at the SMTP level, so this means all SPAM filters are done before Ability Mail Server accepts mail from outlook. If this processing is taking too long you could always move your black / white list filtering to content filtering which is done after the SMTP stage. The only problem with this is that outlook has disconnected so instead of refusing any email outright you instead just have to generate a failure notification email to the sender using the content filtering actions if a mail is rejected. The processing will still take about the same time but now the mail clients like outlook won't have to wait.

[centralusa]

Thanks very much for the feedback