-3
votes
1answer
95 views

Blocking unsubscribe spam

I have SpamAssassin turned on and using RBL in the WHM control panel using the lists from spamhaus. However, these type of e-mails are getting in. Are there any ways to stop them? Example of the ...
1
vote
2answers
161 views

How Reverse DNS does what it does

Hopefully this is not a stupid question, but I cannot find a clear cut answer. Can someone please inform me exactly what 'source address' is used in Reverse DNS? Does rDNS pull the IP address from ...
0
votes
2answers
134 views

Block by file type, but just file extension using MDaemon

I've had users sending copyrighted files (songs, videos) to each other over email. I blocked the file extensions .mp3 etc. What some users have done is to rename files to .doc etc. I cant block .doc ...
5
votes
3answers
4k views

Why does gmail flag my server emails as spam?

I recently moved my server to a new slice at slicehost and since, gmail has been flagging my email as spam. I have added domain keys, created a SPF record, have reverse dns setup, and my ip is not ...
2
votes
1answer
129 views

Outgoing emails from China based VPS rejected or marked as spam

I just switched email service provider from Google apps to a VPS with a Hong Kong host. Now I find a huge part of all outgoing emails ending up in spam boxes and in some cases getting totally rejected ...
2
votes
5answers
873 views

How to configure email server to send lots of transactional emails

My organization is currently outsourcing email delivery to an SMTP service provider. We're considering bringing that back in house to deliver our own emails. We send about 5k transaction emails per ...
1
vote
3answers
611 views

how to stop outgoing email spam

running an email system using roundcube, with about 200 people using it. 99% of them do as they are told and only email clients they have already spoken to, however 1% of them decide to bulk spam bcc ...
4
votes
2answers
1k views

Postfix: content-filter vs. milter

I have a Postfix mailserver with content filtering using AMaViS via the "content-filter" option of Postfix. Now I wonder whether it would be better to use AMaViS as a milter instead of the ...
3
votes
1answer
330 views

How can I explain to dspam that the user “brandon” is the same as “brandon@mydomain”

I am using dspam for spam filtering by running the "dspamd" daemon under Ubuntu 9.10 and then setting up a Postfix rule that says: smtpd_recipient_restrictions = ... check_client_access ...
20
votes
4answers
3k views

Best Practices for preventing you from looking like a spammer [duplicate]

I'd like to feel more confident setting up mail for my clients with regards to false positives. Here's what I know: SPF records are good, but not every spam filter service/software (SFSS) uses ...
2
votes
3answers
777 views

How do you configure sendmail to reject Email with a Date header too far from real time?

A friend of mine using (I believe) qmail has it configured to reject, as SPAM, any incoming Email with a Date: header that is too far from real time. I can't figure out how to do this with sendmail. ...