Questions tagged [spam]

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

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110
votes
9answers
128k 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 ...
108
votes
6answers
60k views

Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User?

This is a Canonical Question about Fighting Spam. Also related: How to stop people from using my domain to send spam? What are SPF records, and how do I configure them? There are so ...
83
votes
8answers
149k 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 ...
82
votes
11answers
89k views

Dealing with HTTP w00tw00t attacks

I have a server with apache and I recently installed mod_security2 because I get attacked a lot by this: My apache version is apache v2.2.3 and I use mod_security2.c This were the entries from the ...
50
votes
5answers
10k 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 ...
41
votes
6answers
2k views

Is it becoming impossible to be a small mail provider?

I operate a small mail server for my private emails, some friends who have websites and two NGOs. In total my server sends between 60 and 400 messages a day. Now a lot of these emails are personal ...
35
votes
7answers
6k views

How can I attract more Spammers hitting my Spam traps?

Currently I have a number or domains that are set up as Email Spam traps. So if I get mails on that domains I can be certain that it is ~100% Spam. I'm using this information to temporarily defer ...
30
votes
3answers
90k views

How do I check a PTR record?

I need to check a PTR record to make sure that a script I have is sending emails which will actually be received by my users and not be incorrectly marked as spam. I understand that the ISP which ...
29
votes
7answers
5k views

Why is it a bad idea to use a customer email as the from address

I've got an application that emails users once they have filled in a form. It uses a no-reply@customerdomain.com as a from address. The customer wants it to use the email from the form as the from ...
29
votes
4answers
850 views

What happened to all the spam?

Don't get me wrong, I'm mostly glad that this happened. However, I want to make sure that the reasons for it happening are sound - rather than there being a problem with our methods. I'd like to ...
28
votes
4answers
13k 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 them. ...
27
votes
6answers
21k views

Why do 'hackers' setup bots repeatedly fill out web forms?

There is something I don't get, one of my web apps has a small form that allows you to enter you name and email address to "subscribe" to a user list for a site I maintain. The site is very low ...
27
votes
4answers
9k 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 ...
25
votes
7answers
20k views

How to stop spammers from sending spam as me

We've starting to receive bounced spam messages and the sender is one of our email address. We know that we don't send spam from that address. We've tried changing the password but we're still ...
24
votes
4answers
116k views

Fixing My MTA's Poor Reputation

I have a web site that needs to send email to customers to deliver files that they have purchased. Reliable email delivery is vital to this business. Unfortunately, most of the emails sent by my ...
24
votes
2answers
23k views

Is the 10-DNS-lookup limit in the SPF spec typically enforced?

My understanding is that the SPF spec specifies an email receiver shouldn't have to do more than 10 DNS lookups in order to gather all the allowed IPs for a sender. So if an SPF record has include:foo....
21
votes
12answers
41k views

Which anti spam DNS blacklists should used?

i want to protect my mailserver with dns blacklists for fighting the spam. there a so many blacklists out there. currently i use: ix.dnsbl.manitu.net cbl.abuseat.org bl.spamcop.net safe.dnsbl.sorbs....
21
votes
4answers
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 ...
18
votes
9answers
2k views

Gmail and Live are making all messages from my server as spam

I'm getting very weird results here. When my server sends an email to my @hotmail or @gmail account, it's marked as spam. When I send email through my server from Outlook to @hotmail, it doesn't get ...
17
votes
2answers
15k views

IIS7 ban IP range [duplicate]

Possible Duplicate: How does IPv4 Subnetting Work? I have a list of IP ranges I would like to ban, an example being: 119.30.47.xx Where xx is anything. I've added the domain and IP ...
16
votes
6answers
3k views

Spam emails regarding Domain Abuse Notices

I have received domain abuse notice email from chloe-gray@icann-monitor.org. The mail asks to download a Word Document which I believe contains a virus. Dear Domain Owner, Our system has ...
16
votes
9answers
27k views

Relatively easy way to block all traffic from a specific country?

I have a web app that has no users in the Philippines, but is constantly bombarded by spammers, carders testing cards, and other undesirable activity from there. I can see in the logs that they have ...
16
votes
3answers
3k views

Is my new gTLD causing it to get filtered as spam?

I have a domain called "*******.international". I decided to go with the new gTLD because it fits the name of the company pretty well. I have an automated emailer setup to send emails to our clients' ...
15
votes
5answers
13k views

How to minimise SpamAssassin (spamd) memory use

I'm using SpamAssassin on Debian (the default configuration with Pyzor, AWL and Bayes disabled, and sa-compile enabled), and each of the spamd child processes consume around 100 to 150MB of memory (...
14
votes
10answers
6k views

Using fake MX records to combat spam

I have a client that is getting heavily spammed.. It's the 15th of the month and POP3 bandwidth is almost 100 GB. There are only 7 e-mail accounts on this domain. I installed SpamAssassin set it to 5 ...
14
votes
11answers
20k views

Good & free Exchange spam filter [closed]

Do you know a good (and free, if possible) Microsoft Exchange 2003 spam filter?
14
votes
1answer
16k views

What is preferable, “no-reply@” or “noreply@”? [closed]

Having a service that sends out notifications to users, I'm currently thinking about changing the sender email address from "info@" to something more meaningful. Since a reply never makes sense, I'm ...
13
votes
1answer
39k views

How to resolve problems with spf / softfail?

I'm having problems with Google rejecting mail because of SPF problems. I thought I had this fixed, but evidently not... The mail is being sent from a Drupal site running mimemail. A message that ...
12
votes
9answers
20k views

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 ...
12
votes
2answers
4k views

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 ...
12
votes
2answers
2k views

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 ...
12
votes
3answers
5k views

Is SRS rewriting absolutely necessary for a forwarding mailserver?

I am operating a Postfix email server for my domain, say mydomain.com. It mostly acts as a forwarding email server: users receive an email address @mydomain.com, but usually elect to have their ...
12
votes
10answers
5k views

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 ...
12
votes
3answers
1k views

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: ...
11
votes
2answers
757 views

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 ...
11
votes
4answers
4k views

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 (...
11
votes
3answers
33k views

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 ...
11
votes
5answers
11k views

Is there any alternative to SpamAssassin? [closed]

I'm looking for an alternative to Spamassassin. Anyone tried rspamd ?
11
votes
3answers
22k views

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/...
11
votes
3answers
7k views

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, ...
11
votes
2answers
35k views

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/...
11
votes
2answers
8k views

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://<my server>:80 http://yahoo.com But the response from apache is: ...
10
votes
10answers
5k views

Setting up a fake email address to trap spammers

I have heard it suggested that we set up a special email address, with it's only purpose being to be harvested. Then blacklisting every sender that targets this address. I'm wondering: if anyone ...
10
votes
7answers
3k views

Does SMTP greylisting a) stop much spam and b) stop much legitimate mail?

I've just set up an SMTP server on a relatively little used domain using Postfix and enabled greylisting with SQLGrey. So far it seems to be working OK, and while there's the slight irritation of ...
10
votes
5answers
3k views

Recommendations for SMTP services for massive mailing [closed]

What is the recommendations for SMTP services for massive mailing? Let me clarify, most of the free SMTP services (Gmail, Yahoo, Hotmail, etc...) has limits about the amount of messages you can send ...
10
votes
5answers
39k views

How to report spam to blacklists

Is there a central place to report spam to various blacklists ? I regularly report to spamcop, but I do not see the addresses I reported as listed. (I guess nobody else bothers with my regular ...
10
votes
1answer
431 views

Microsoft is blocking mail from entire netblock. ISP doesn't know what to do?

I recently moved a client from basic T1 service to a multi-site MPLS solution with same vendor. The ISP, XO Communications, provided a decade of stable service as a T1 provider. The process of moving ...
10
votes
1answer
928 views

Postfix emails detected as spam with gmail [duplicate]

I know that there are a few posts about this and I have been reading them for a while now but still, I can't resolve my issue. I’m running ISPconfig with postfix and I can’t figure out why my ...
9
votes
3answers
881 views

Does “~all” in the middle of an SPF record signal the end of the record when it is parsed?

Our company's SPF record format is as follows: "v=spf1 include:_spf.google.com ~all a mx ip4:X.X.0.0/23 include:spf.example.com ?all" So we have an "~all" in the middle of our SPF record. On the ...
9
votes
3answers
10k views

Send spam mail to a special folder using postfix

I have a postfix server running amavis and SpamAssassin to help filter spam. Messages that are detected as spam look like this when delivered into the user's Maildir: From tom@tom-mint Fri Mar 15 01:...