Linked Questions
84 questions linked to/from Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User?
111
votes
9
answers
140k
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 ...
- 1,437
98
votes
8
answers
196k
views
How to send emails and avoid them being classified as spam?
This is a canonical question about how to handle email sent from your server being misclassified as spam. For additional information you may find these similar questions helpful:
Best ...
- 1,835
60
votes
2
answers
24k
views
What are SPF records, and how do I configure them?
This is a canonical question about setting up SPF records.
I have an office with many computers that share a single external ip (I'm unsure if the address is static or dynamic). Each computer ...
- 759
54
votes
5
answers
13k
views
Is greylisting still an efficient method for preventing spam?
I've used greylisting on my servers for many years, but I don't know how effective it is nowadays.
Is it still good for fighting spam in 2012?
Or is the typical spammer MTA capable of resending ...
- 724
30
votes
4
answers
12k
views
Prevent mail being marked as spam
This is a canonical question about avoiding outgoing mail being classified as spam.
Also related:
Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User?
What ...
- 405
21
votes
5
answers
3k
views
Is it good practice or too draconian to reject mails from mailservers with no RDNS
I've recently dropped SpamAssassin and am now basing spam rejection on DNSRBL's, grey-listing and other basic tests and I'm wondering whether I should also block hosts that don't have a valid RDNS ...
- 596
21
votes
4
answers
3k
views
What are the best methods for catching snowshoe spam?
I'm using Smartermail for my small mailserver. We've been having a problem lately of getting waves of snowshoe spam that follow the same pattern. They come in batches of 3 or 4 at a time. The ...
- 436
13
votes
5
answers
12k
views
Is there any alternative to SpamAssassin? [closed]
I'm looking for an alternative to Spamassassin. Anyone tried rspamd ?
- 139
12
votes
2
answers
36k
views
In postfix, how to enforce tls + auth over 587 while leaving tls optional for 25
I would like to host mail services for some domains. I have succesfully setup postfix to consult sql for those virtual domains. What I would like to do is:
For connections on 25:
Deny relaying (...
- 329
11
votes
3
answers
49k
views
Helo command rejected: Host not found - Setup postfix to accept sending mails from my home server through my public server
I would like to receive system emails from my home server. So I'm trying to configure postfix to do that through my public server. My public server has a fixed IP, while my home server is in a private ...
7
votes
6
answers
5k
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
- 457
7
votes
1
answer
8k
views
Does postfix reject spoofed senders?
Is there a reliable way to reject incoming mails with a spoofed e-mail address?
What kind of checks does postfix run normally on incoming mails?
does postfix check the reverse dns by default?
does ...
- 683
7
votes
4
answers
13k
views
Is it possible to find a list of all DKIM keys for a domain?
a DKIM-record is identified by its selector, which might be default, dkim or something else alltogether (and there might be multiple).
When making sure that an e-mail's content is valid, the DKIM ...
- 169
6
votes
4
answers
4k
views
How can I block outside mail FROM [email protected]?
A security firm has been testing my mail server and claims my Postfix daemon is an open relay. The evidence is as follows (valid public IP for mail.mydomain.com has been changed to 10.1.1.1 for ...
- 119
6
votes
1
answer
20k
views
Significance of NOQUEUE: reject: RCPT in Postfix log?
I set up brand new Postfix server last night and did not configure at all yet, just did the install. So, I logged in this morning to finish the configuration and notice that there is stuff in the log:
...
- 487