85
votes
9answers
68k views

How to stop people from using my domain to send spam? [duplicate]

I receive Mailer Daemon messages saying certain emails fail. My domain is itaccess.org which is administered by Google apps. Is there any way I can identify who is sending emails from my domain, and ...
6
votes
6answers
3k views

Spam prevention tips for Postfix [duplicate]

Without using SpamAssasin, or similar, what are your best tips for preventing spam. Please try and provide config examples :D
1
vote
4answers
3k views

Prevent spamming [duplicate]

How to prevent spamming in Cpanel / Linux server ?
2
votes
3answers
3k views

Should I reject email on SPF and/or DKIM failures? [duplicate]

I’m administering a mail server (cPanel/WHM) running Exim. It handles normally a few hundreds incoming emails per day for our customers. I’m not sure if I should reject SPF and/or DKIM failures for ...
-1
votes
1answer
1k views

Suddenly Gmail and Hotmail block our emails [duplicate]

Starting from yesterday, all emails sent from our server are being rejected by Gmail and Hotmail. Everything was working properly until now. Here are the error messages received: Gmail Failed ...
-1
votes
1answer
1k views

sendmail - Server Sending Spam? [duplicate]

for the past day my server is being used to send a spam. I'm using the Amazon Linux Distro (RedHat based). It has sendmail 8.14.4. It is setup to require authentication, SSL etc. Below are some ...
0
votes
2answers
373 views

DKIM, spam probability, signing with key at mail server vs sender domain? [duplicate]

I'm working on an email marketing tool and so far we've been recommending our customers to set up an SPF-record (Sender-ID) and a DKIM-record, we also have our own SPF-record on the mail server and a ...
0
votes
4answers
690 views

Stopping incoming spam with sendmail [duplicate]

I am having an issue due to a "smart" sysadmin that made some choices while I was away for two months: Spam. I manage probably close to 10,000 web/mail sites. He decided to allow all mail to ...
0
votes
1answer
210 views

Project Honeypot says my mail server has become a spammer [duplicate]

I need help diagnosing this: http://www.projecthoneypot.org/ip_66.18.204.186 It says my server has been sending spam for 4 months! I try to be a responsible mail server admin, I hate spam, I do ...
0
votes
1answer
183 views

can someone explain this exim mainlog lines? [duplicate]

i dont understand this lines in exim mainlog , may anybody explain this ? my server is sending spam and i need to stop it. 2015-04-25 07:51:42 1Ylqf0-0000TF-G1 DKIM: d=mandrillapp.com s=mandrill ...
0
votes
1answer
35 views

How to prevent spammers sending bogus@mydomain emails out of my name [duplicate]

Lately I receive a lot of Delivery Status Notification (Failure) e-mails. Bogus spam email is sent from blablaxx@mydomain to other emailadresses, and bounce back to my catch-all info@mydomain with ...
0
votes
1answer
122 views

Prevent Email Going to Spam [duplicate]

I've set up my own server and I'm really struggling to stop any outgoing email go to spam. I've used allaboutspam and mail-tester.com to test it and they both come back with perfect results. No ...
0
votes
1answer
77 views

I guess that my mail server is unprotected and spammers are using my mail server to spam myself [duplicate]

Since I switch to my own mail server (I folowed this two tutorials: https://www.linode.com/docs/email/postfix/email-with-postfix-dovecot-and-mysql and ...
0
votes
2answers
76 views

How reliable is validating email domain by reverse DNS MX record checking [duplicate]

This question is not about how to protect against spam or validate a particular email user. But how reliable is validating emails domain (does it exists at all) by reverse dns. What are the pitfalls ...
0
votes
1answer
69 views

Blocking spam with SpamAssassin [duplicate]

I have a server that runs websites and exim for e-mail. I've added countless RBLs including barracuda to try and cut back on incoming spam. However, they still keep coming in. The clients use ...

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