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Questions tagged [spam]

Unsolicited e-mail, comments or posts, often sent out in large volumes; possibly but not necessarily commercial in nature

Spam can refer to:

  • Junk e-mail
  • Unwanted posts on a website
  • Unwanted comments on a post on a website
  • A large number of posts designed to crash a system rather than provide useful content

For our canonical Q&A about how to prevent email you send from being flagged as spam, see How to send emails and avoid them being classified as spam?.

1384 questions
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My EC2 instance's email is being spam blocked by gmail

I'm not sure what to do about this. When on a different IP (the same server set up, domain etc), we had no problems with email deliverability. Since transferring to EC2, despite having the AWS imposed SMTP limits removed, I'm finding that my…
chrism2671
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Detect spammers on my server

I recently got one Undelivered Mail Returned to Sender while sending my newsletter to one of my 1500 customers. My website uses a double-opt-in procedure to make sure, the user explicitly want to receive my newsletter. The error message: smtp; 554…
koseduhemak
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All External Mail to Office 365 Fails SPF, Marked as Junk by EOP in a Hybrid Deployment

In short: legitimate emails are landing in Junk folders as EOP (Exchange Online Protection) stamps email messages as junk (SCL5) and SPF-failed. This happens with all external domains (e.g. gmail.com/hp.com/microsoft.com) to client’s domain…
wandersick
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13
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3 answers

Sendmail: Sender address rejected (Domain not found)

I'm running into problems with sending mail on our webserver. Some mails are sent and delivered without any problems (eg Gmail), while others are deferred with "Sender address rejected: Domain not found" I understand that this is a spam protection…
JonoCoetzee
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5 answers

Is there any alternative to SpamAssassin?

I'm looking for an alternative to Spamassassin. Anyone tried rspamd ?
dynax60
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12
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2 answers

How can I reject base64 encoded spam email?

I just received couple of mails with similar content which were encoded with base64. Now I want to reject or discard these kind of emails using body check. Before I had in my body_checks something like this: /Quanzhoucooway/ DISCARD But since the…
user134969
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Email from our server tagged as junk by Hotmail Smartscreen unable to inform Hotmail that it is legitimate

Since more than 1 month ago we are having our email from one of our servers systematically tagged as junk by Hotmail Smartscreen filter. We have taken the following actions/measures without success: Reverse DNS matching the sender IP. SPF,…
Miguel Telleria de Esteban
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10 answers

Where to go to see if my IP is blacklisted as a SPAM

This has happened before and some mail servers will tell you that your IP has been blacklisted (RBL, CBL, etc) but I can't find that site to check anymore and searches result in a site that may or may not be legitimate.
Sheldon McGee
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12
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7 answers

Are SPF needed for domains that do not send mails and do not have MX record?

I have some domains registered that do not send mails. I have totally removed MX record for these domains on my DNS. Is it still useful to set an SPF record in order to avoid spammer to send mails as these domains? I read here that for domains that…
Marco Demaio
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4 answers

Postfix check outgoing mail for spam

How can I force postfix to check (and log/flag/etc) all outgoing mail for spam? Just want to make sure I'm doing my part on my servers. EDIT: Postfix config, as requested. main.cf # See /usr/share/postfix/main.cf.dist for a commented, more complete…
Glen Solsberry
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4 answers

How I stop spam backscatter rendering email on my domain unusable?

Some miscreant is using non-existent accounts on my domain as a forged sender for spam emails (i.e., sdfhdfsg@mydomain.com). All the out-of-office and spam rejection emails are coming back to me (since my domain is set up to pass me anything…
Rob Cowell
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11
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2 answers

How can I reduce the damage of stolen mail accounts?

Currently I’m offering some webhosting to a few advertising agencies for their premium customers. But currently I have a great problem with the E-Mail Service. In the last week, the E-Mail Accounts of about 7 companies were stolen and used to send…
user39063
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11
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2 answers

How can I test if my apache server is an open proxy?

Is there a curl command that will validate if a server is acting as an open proxy? I've tried curl --proxy http://:80 http://yahoo.com But the response from apache is: Description: Could not process this "GET" request.
Will
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3 answers

Gmail rejects emails. Openspf.net fails the tests

I've got a problem with Gmail. It started after one of our trojan infected PCs sent spam for one day from our IP address. We've fixed the problem, but we got into 3 black lists. We've fixed that, too. But still every time we send an email to Gmail…
pablomedok
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11
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5 answers

Delete from mailq where subject matches

I have a mailq which is getting backed up with multiple emails with the same subject line. I would like to delete all emails in the mailq that match a particular subject line so they don't get sent. Any ideas how to do this? Pretty urgent as its…
David
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