asked on

Spam comming through firewall

We recently installed a new firewall. Afterwards, our smartphones were not able to send mail (but could receive). We loosened the SMTP access rules, but now we're getting spammed to death.

Currently, we allow SMTP from ANY source interface, ANY Source IP to our mail server. Before, we only allowed SMTP from our MX servers to our mail server.

Any help would be great. Thanks.

ChopperCentury

In order to receive mail from the outside you have to allow any source to destination IP of mail server with service of SMTP. If you do not have a SPAM filter in place, you will be SPAM to death. You can put in rules to block many of the foreign SPAM king networks, which should cut a dent in a lot of SPAM but still need a filter.

fieldb1

ASKER

Your first sentance is not in accordance with my experience. Before allowing any source to mail server IP with SMTP, we only allowed traffice from our spam filters. However, our smart phones could not send mail. I would happily undo the any source to our mail server and revert to SMTP, from spam filter (mx), to mail server; however, our smart phones aren't able to send email that way.

ChopperCentury

Ok this is different than your original post. You did not mention having a spam filter in the mix.

ASKER CERTIFIED SOLUTION

rickygm

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

fieldb1

ASKER

Ok, thanks. I had considered using an alternative port. Why 587 and not, say, 26?

We do use SMTP authentication.

SOLUTION