Questions tagged [spam]
Unsolicited e-mail, comments or posts, often sent out in large volumes; possibly but not necessarily commercial in nature
1,411
questions
111
votes
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answers
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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 ...
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111
votes
6
answers
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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 ...
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99
votes
8
answers
198k
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 ...
- 1,845
82
votes
11
answers
91k
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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 ...
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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 ...
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49
votes
5
answers
171k
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 ...
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44
votes
7
answers
3k
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 ...
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36
votes
7
answers
7k
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 ...
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31
votes
7
answers
6k
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 [email protected] as a from address. The customer wants it to use the email from the form as the from ...
- 421
30
votes
6
answers
30k
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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 ...
- 1,309
30
votes
4
answers
12k
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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
29
votes
2
answers
28k
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....
- 2,374
28
votes
4
answers
15k
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.
...
- 14k
28
votes
4
answers
1k
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 ...
- 5,352
26
votes
4
answers
138k
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 ...
- 840
25
votes
7
answers
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 ...
- 1,003
25
votes
5
answers
8k
views
Does DKIM alone not solve the spam issue? Why do I need SPF?
FINAL EDIT : I was completely wrong about DKIM it seems, the signing domain does not have to be the same as the sender domain, thus the whole premise for my question is flawed. A lot of thanks to Paul ...
- 521
23
votes
9
answers
44k
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 ...
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 ...
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20
votes
12
answers
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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....
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20
votes
1
answer
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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 ...
- 2,460
19
votes
9
answers
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 ...
- 293
17
votes
4
answers
4k
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' ...
- 273
17
votes
2
answers
21k
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 ...
- 385
16
votes
6
answers
4k
views
Spam emails regarding Domain Abuse Notices
I have received domain abuse notice email from [email protected].
The mail asks to download a Word Document which I believe contains a virus.
Dear Domain Owner,
Our system has ...
- 321
16
votes
3
answers
8k
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 ...
- 255
15
votes
10
answers
7k
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 ...
- 781
15
votes
5
answers
16k
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 (...
- 909
14
votes
9
answers
25k
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 ...
- 2,649
14
votes
1
answer
43k
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 ...
- 723
14
votes
11
answers
21k
views
Good & free Exchange spam filter [closed]
Do you know a good (and free, if possible) Microsoft Exchange 2003 spam filter?
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13
votes
7
answers
20k
views
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 ...
- 599
13
votes
2
answers
7k
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 ...
- 449
13
votes
2
answers
4k
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 ...
- 271
13
votes
3
answers
61k
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 ...
- 315
13
votes
2
answers
16k
views
How does DKIM work when sending emails from multiple sources/servers?
So if I'm understanding DKIM correctly, it basically is a public/private key type of service. However, how does this work if you send emails from multiple servers/sources? For instance, I have a ...
- 141
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
13
votes
3
answers
50k
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/...
- 318
12
votes
10
answers
6k
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 ...
- 441
12
votes
2
answers
18k
views
Emails are constantly marked by Outlook.com as SPAM
One of our domains is constantly marked by Outlook as SPAM, despite the adequate setup that is reported as properly configured and validated by many on-line tools, among those, the mxtoolbox.
Please ...
- 273
12
votes
4
answers
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
5
answers
82k
views
How do I remove IP from sorbs.net blacklist?
Our email server has ended up in the sorbs.net blacklist and we're going round in circles trying to get it removed, currently this is causing down-time between our suppliers.
I am a developer and not ...
- 327
11
votes
5
answers
14k
views
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. ...
- 851
11
votes
2
answers
794
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 ...
- 221
11
votes
4
answers
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., [email protected]).
All the out-of-office and spam rejection emails are coming back to me (...
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11
votes
1
answer
14k
views
Postfix, how can I reject spam from unknown IP (no DNS)
Despite all efforts to filter spam, I'm still getting spam from unknown even after I've set main.cf to not allow it and to check the DNS etc. Even after adding a pcre: to REJECT /.unknown./ some of ...
- 111
11
votes
4
answers
28k
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/...
- 1,546
11
votes
3
answers
10k
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, ...
- 133
11
votes
2
answers
15k
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:
...
- 362
10
votes
10
answers
6k
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 ...
- 23.5k