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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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 ...
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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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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
111
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9
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 ...
- 1,437
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votes
4
answers
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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.
...
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23
votes
9
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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 ...
29
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2
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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....
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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/...
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4
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How does a Reverse DNS lookup work with regards to spam filters?
I have heard that most spam filters use a reverse DNS lookup on the originating IP address of the sending SMTP server (or something like that) as part of the verification process. I want to make sure ...
- 193
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3
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How to limit the From header to match MAIL FROM in postfix?
SMTP clients are required to pass user authentication before sending emails to other domains (relay). And we can use smtpd_sender_restrictions to make sure the MAIL FROM address matches the ...
- 191
8
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4
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What to do with an out-of-warranty Barracuda Spam/Web filter?
I'm working with an organization that would like to start using a old Barracuda Spam Filter 300 unit. I've sold and configured plenty of these, but was surprised to see that this unit's warranty ...
- 199k
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6
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How do you detect a spambot on your network?
I help manage a small network of about 40 computers. We are running an Exchange 2003 mail server.
What is the best way to find which machine is infected by a spambot? I've tried installing anti-virus ...
- 73
44
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7
answers
3k
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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 ...
- 742
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5
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How do I configure SPF for multiple domains on a server? (also allowing gmail as a sender)
SPF (Sender Policy Framework) seems like a good way to combat spammers/spoofing.
However, despite reading the explanations several times, I'm not quite understanding how to configure it correctly.
...
- 594
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5
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How do I spamtrap with Postfix?
How do I setup spamtraps with Postfix so clients that send to trapped addresses are prevented from sending me more spam?
- 6,848
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2
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postfix sending mails to unknown addresses
I was checking my munin tables and saw a huge list of deferred mails in postfix and looking into /var/log/mail.log gave me an idea: I am sending mails to unknown mail addresses:
Dec 23 08:21:32 ...
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11
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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 ...
- 11k
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7
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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
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2
answers
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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 ...
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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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Avoid creating backscatter on a Postfix forwarding server
I run a Postfix server that hosts a small, alias-based mailing list. Let's say people@myserver forwards to alice@someprovider and bob@someotherprovider. Now, alice@someprovider might use a more ...
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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 ...
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2
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DNSBLs for IPv6
Spamhaus and other well-known DNSBLs don't yet support IPv6, and I'm not sure they ever will. What alternatives are there for spam filtering on IPv6?
One approach is to rely entirely on content-...
- 3,706
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Postfix Whitelist before recipient restrictions
Alright. Some background. We have an anti-spam cluster trucking about 2-3 million emails per day, blocking somewhere in the range of 99% of spam email from our end users.
The underlying SMTP server ...
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How to make spamassasin reject mail based on score?
I am running Linux with Postfix, Dovecot, Postgrey and spamassasin/spamd.
This is my main.cf
smtpd_recipient_restrictions = permit_sasl_authenticated,
...
- 608
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1
answer
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Why would Spamhaus continue to add an IP to the CSS when that IP hasn't sent email recently?
For the last six months I have been locked in battle with the Spamhaus CSS SBL, having to regularly check if the IPv6 address of my Exim4 server has been listed and, if it has, manually delisting it. ...
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votes
6
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Send email on behalf of clients
We're a communications company primarily doing printing of statements / utility bills, then mailing them out in the post.
A few clients have asked for e-Delivery. Pretty much take the print output as ...
4
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2
answers
5k
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Firewall rule to only allow Postfix to send email through SMTP on port 25
As suggested in How do you detect a spambot on your network? how can I setup firewall rule to allow only Postifx to send emails using SMTP on port 25 and disallow all other applications to send on ...
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Barracuda tagging email with 'date grossly in the future.'
I have a Barracuda 300. Granted it's running on some old firmware and the Energize updates are quite outdated. I'd like to update them, but, not my financial decision to do so.
Starting around the ...
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2
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How do I throttle outbound email with sendmail
I know, I know, I should switch to Postfix. But in the meantime, how do I throttle outbound email (especially email to a single domain) in Sendmail?
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2
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Postfix sends email to spam (gmail, hotmail)
I recently installed a postfix + dovecot + dkim multi domain, multi user, multi alias mail server on my debian squeeze system. Everything works except for one big issue that basically makes the whole ...
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Minimize the chance my email is blocked/filtered as spam
I'm running a web-based store where order confirmations are sometimes blocked and don't reach the intended user. The structure of the business model is such that our product is marketed to the end-...
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Receiving spam from my own email address. postfix
for 2 weeks now I keep receiving spam emails sent from my own address.
Here's an example :
Apr 2 10:15:13 hostname postfix/smtpd[28874]: warning: hostname 212.156.246.74.static.turktelekom.com.tr ...
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Is there any way to see why Outlook's client junk mail filter is marking a message as spam?
I have some users running Outlook 2007 connected to an Exchange server, and they're complaining about mail ending up in their junk box. There's no X-SCL tag in the mail headers so this filtering must ...
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4
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Postfix- open relay. How to configure so it is not?
I have setup Postfix but am having trouble with the setup.
Whenever I used to send emails to the server, it reject my mails saying 'Relaying Denied', so I changed the following in main.cf:
...
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5
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How to prevent mail from our website going into spam mail of users?
I work for an educational services company based in India. We've around one million students enrolled as users. We're frequently facing the problem of our bulk mailers regarding upcoming exams, new ...
M. Bishan
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1
answer
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Spam coming from domain, but from a user that I don't have [duplicate]
Possible Duplicate:
How to stop people from using my domain to send spam?
I have google apps handling the email for my domain (musikpitch.com). Some Cialis spam got sent with the email address ...
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vote
2
answers
455
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Our IP was listed by Spamhaus - how can we prevent this from happening again?
I'm the technical assistant at a small-town public library where we run our own e-mail. If it matters, it's Postfix on an Ubuntu 18.04 box. Gateway / firewall is a 16.04 box with port forwarding set ...
- 171
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vote
1
answer
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PermError SPF Too Many Lookups and Reduction
My current SPF record is as follows:
v=spf1 mx include:servers.mcsv.net include:xero.com -all
The above cause the SPF validation to fail.
Using http://mxtoolbox.com/SuperTool.aspx?action=txt, I can ...
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1
answer
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I can't send email from my server to gmail addresses
I'm using postfix, and have setup spf, dkim, and domainkeys. I can get my email to go to Yahoo, but not gmail. Here's the headers from an email send to Yahoo. Yahoo reports the email as domain key ...
- 1,074
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5
answers
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Barracuda spam filter alternative - virtualization/appliance friendly?
I've sold and deployed Barracuda spam and web filters for years. I've always thought that the functionality was good (Barracuda Central, easy interface, effective filtering), but the hardware on the ...
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5
answers
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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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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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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 ...
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4
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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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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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9
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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 ...
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5
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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 (...
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1
answer
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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 ...
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5
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Is there any alternative to SpamAssassin? [closed]
I'm looking for an alternative to Spamassassin. Anyone tried rspamd ?
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