All Questions
Tagged with email-server spam
191 questions
0
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38
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Why is Gmail labelling DKIM signed mail as spam? [duplicate]
I am running a Postfix with OpenDKIM for DKIM signing.
In the past, I have used a single domain and have not encountered issues with mail being labelled as spam.
I currently have multiple domains on ...
- 13
0
votes
0
answers
121
views
Dovecot Mailserver moves mails with "List-Unsubscribe" header to junk, although no spam settings configured
I have my own mailserver setup with postfix and dovecot on an Ubuntu 20 server. The setup is very standard (postfix using mbox files) and has been working nicely for a long time. However, there is an ...
- 121
1
vote
0
answers
146
views
My email server IP is blacklisted, how can I resolve it?
The IP of our email server 154.116.254.147 was added to the UCEPROTECTL2 blacklist. The error message we received is as follows:
"I am deeply sorry, but I was not able to deliver your mail to the ...
2
votes
0
answers
69
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how to protect postfix mail from gmail spam [duplicate]
I am experiencing an issue with the BDIX (Local Bangladeshi server) server.
I have set up a mail server on the local BDIX server using postfix with aapanel.
I have configured SPF, DKIM, and DMARC in ...
0
votes
0
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65
views
SPAM and SPOOF emails from postfix mailserver
I created and configured a postfix server, basically its an smtp-only server. I added the domain i want to use in postfix main.cf, and also added other domains in virtual file. I installed configured ...
0
votes
1
answer
106
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Weird email spam issue. Google Domain Exchange email server
We have a client who is blocking our email domain.
Their IT wrote this to us. I've never seen this be an issue before.
You are hosted on Google but have entries referring to Microsoft email protection ...
- 101
0
votes
1
answer
284
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Amavis outbound mail filter for Postfix?
Running Postfix on Ubuntu 22.04, I'd like to make sure all outgoing mail originating from the server (eg mail forms on websites and stuff) is filtered for spam and malware. I'm using Amavis, which is ...
- 566
0
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1
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580
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How to make a mail server spam "proof"
I work for a German company that sends several thousand emails to our customers every day. Our employees send their emails via Microsoft 356, but the system does not use a mail server and sends emails ...
- 15
3
votes
2
answers
987
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Changing hostname for the purpose of email delivery
I have email delivery issues, and MXtoolbox says "Reverse DNS is not a Valid Hostname". I have A and AAAA records for domain.com and mail.domain.com. The data center has set up reverse DNS ...
- 147
0
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0
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584
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Sendgrid IP Address Consistently Blocked on RATS-Spam
Overview
For our application, we use SendGrid to send emails to many of our users. Recently over the past few weeks, our SendGrid IP addresses have been added to the RATS-Spam blacklist multiple times....
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0
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1
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723
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Completely block any outgoing emails
I have a server with Postfix, running in Docker. The server is supposed to only receive emails, not send them.
I added the following iptables rules to try to block anything getting out from port 25:
...
- 103
1
vote
1
answer
3k
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Spamhaus is blocking several customers since a couple of days?
I received a couple of complaints from customers that got their emails rejected.
I haven't changed my config, so this must be an issue with spamhaus.
I'm running Postfix with these settings for ...
- 353
7
votes
2
answers
1k
views
How can I create and update the existing SPF record to allow more than 10 entries?
How can I include another SPF record if my existing domain already has 10 lines of SPF records in the TXT record?
I wanted to add these two:
include:mailgun.org
include:sendgrid.net
This is my ...
- 1,335
0
votes
1
answer
842
views
Send email from Heroku server using gmail account and PHPMailer
I have a Heroku app which has a php script that send out an email. The email sent always goes to spam.
Let's say the heroku app is mywebsite.herokuapp.com and my email is [email protected]. Based on ...
- 101
1
vote
1
answer
212
views
After adding a new DNSBL to Sendmail, how can I resubmit an email to see if it will be rejected?
TL;DR
How can I fool my own sendmail into thinking an email comes from a particular ip address, so that it rejects the message due to a DNSBL match?
Details:
I run my own mail server, and most spam is ...
- 83
3
votes
1
answer
2k
views
Why does rspamd consider an odd number of URIs in an email to be an indicator of spam?
Rspamd has many email spam heuristics, and one of them is URI_COUNT_ODD. This heuristic seems to just count how many URIs are in the body of the email, and adds 1 to the score if the number is odd. ...
- 139
0
votes
1
answer
672
views
What to do if a specific postfix/dovecot user's account is hacked and being used to send spam?
I'm running a postfix/dovecot mail server. This morning, I discovered it was unresponsive. Turned out, /var/log was full. It appears one of the users has had their account hacked and it's being used ...
- 439
1
vote
0
answers
301
views
Google Postmaster: IP reputation of subdomain and main domain identical
We have a main domain, example.com. We use this to send regular emails via Google GSuite.
We also have a subdomain, say sub1.example.com. We use this to send campaign emails through an email marketing ...
- 111
0
votes
0
answers
394
views
DKIM validation fails only on Outlook
I'm configuring OpenDKIM to sign miltiple domains with the same key on Pstfix. I followed this tutorial with s=mail and d=example.com.
SigningTable:
* mail._domainkey.example.com
KeyTable:
...
- 11
0
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0
answers
263
views
Discard an email in postfix when the reply-to address is different from that of sender
I've setup virtualmin and the emails are working fine with the Postfix server. However I'd like to add a feature where, in case somebody tries to abuse the server and tries to send an email with a ...
- 1
0
votes
1
answer
71
views
Is it ok (regarding spam) to use yahoo to send email from our domain [email protected]?
I m enough of seeing my email arriving in spam folder. I would like now to send my emails not from my smtp server but from yahoo mail server. When you have a yahoo account, you can choose to send ...
- 133
2
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0
answers
1k
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How to solve '521 5.7.1 Service unavailable; client x.x.x.x blocked using Return-Path'?
How to solve or interpret following error? I'm not sure if anything should be done on client (sender or sending account of a domain) or ask remote postmasters for help.
<[email protected]> (...
- 617
0
votes
2
answers
306
views
Suspicious Exchange message queues filling up disk space
So i came across my HD space getting full too quickly and after doing some inspecting with wireshark and powershell. It seems my email server is being used as a relay for spam.
I closed port 25 on my ...
- 197
1
vote
1
answer
3k
views
emails to Yahoo are ending up in SPAM folder despite spf=pass, dkim=pass and dmarc=pass
Are we possibility having a reputation problems with Yahoo emails?
Yahoo raw mail header finds my policy I published: dmarc=success(p=REJECT,sp=REJECT)
Emails to clients at Google and Outlook are not ...
- 294
0
votes
0
answers
46
views
How do I ensure that only my e-mail server is sending e-mail through my network?
This is a follow-up to Our IP was listed by Spamhaus - how can we prevent this from happening again? - unfortunately, it is happening yet again.
I was thinking that people could have malware on their ...
- 171
1
vote
0
answers
621
views
Yahoo Mail server constantly deferring mail from my server "due to user complaints"
I have a 100% no-spam score on mail tester.
Have no problem with Gmail server, all users getting my emails.
Have everything like SPF and other spam related criteria enabled.
Yet, Yahoo mail server ...
- 111
1
vote
0
answers
386
views
The DMARC test failed but we didn't find any obvious reason why
One of our users recently found out his emails are going to spam for some reason. This made me dive into everything and the last thing I can't seem to figure out is the Dmarc.
We're using gmail for ...
0
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1
answer
198
views
Why are my Postfix mails recognized as Spam? [duplicate]
I have a Postfix mail that I have configured pretty good. mail-tester.com gives me a 10/10.
I have tested on both Google and Yahoo, and checked their headers. Nothing seems to be wrong in the headers.
...
1
vote
2
answers
534
views
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
0
votes
1
answer
114
views
Drop newsletter emails with Postfix
There is an option, i have seen in Fortimail, that makes you able to filter/drop all newsletter emails.
I don't understand how Fortimail detects these type of emails.
And I am keen to know whether ...
- 793
6
votes
1
answer
2k
views
Yahoo blocked emails after changing mail server public IP address
We have two exchange edge server and we want to change their public IP addresses. Changing one of the server IP addresses (and related DNS records) was done successfully and emails are delivered to ...
- 251
0
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1
answer
105
views
Mailserver sufficient to pass as non-spam with Gmail
I am coming to the point of thinking this is beyond my ability to accomplish.
I have repeatedly built new servers on Digital Ocean (3 so far) with Postfix, Dovecot, DKIM, pretty much everything out ...
- 296
0
votes
2
answers
3k
views
How to REJECT email using SpamAssassin
Is it possible to reject emails, like it is done in Postfix using header_checks, using SpamAssassin? Normally, the SpamAssassin only adds the spam flags and by default adds the word SPAM in the ...
- 179
0
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0
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126
views
EC2/EIP email flagged as spam
My company is delivering email out of an ec2 instance using Postfix, but messages are sent to the spam folder in all major providers (Gmail, Outlook, Yahoo). We have an EIP associated with this ...
0
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0
answers
101
views
Postfix only forward catch all to stop spam
I have two catch all addresses set to forward to a gmail account and today i got a message from my hosting saying that they have blocked port 25 on my vps due to it sending spam out.
how would i only ...
- 1
0
votes
0
answers
329
views
Mail issues only with Google App domains
I have a local mail server set up. It is connected via a dedicated IP (with an appropriate PTR record). I have DKIM, DMARC, and SPF set up.
My domain has been added to Google's Postmaster Tools and ...
- 153
2
votes
2
answers
2k
views
Back up Rspamd Spam/Ham databases
I use Rspamd to filter my emails from spam.
The spam filter has already been trained with more than 300.000 emails.
Is there a way to save this "knowledge" or transfer it to another system?
- 167
0
votes
1
answer
73
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Emails still going to Gmail & Hotmail spam after removing host from several blacklists
As I mentioned briefly in the subject the IP address of our mail server got blacklisted a while ago. One of the sites on the server got hacked, which resulted in the addition to a couple of blacklists....
- 135
-2
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1
answer
128
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Abuse report for spamming...abuse report [closed]
Few weeks ago, i activated on my server on automatic abuse report mail when someone try to brute force my SSH, i did it because i got an average of 3000 spamming IP each weeks.
But today, my ISP send ...
- 226
1
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2
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320
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Is this correct for a SPF record based on our setup?
Our company has a SMTP server that sends mail out on behalf of our customers. So a customer would log into our system, go to a specific section, and can fill out a form to send an Email to whoever ...
- 209
1
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0
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59
views
Will enabling non-delivery notifications cause more spam?
In the past we received a lot of spam email. The past year it was a lot less and we would like to keep it that way offcourse.
We are a construction company and we receive a lot of construction ...
- 111
0
votes
0
answers
751
views
My postfix server rejects my python script - "Client host rejected: cannot find your hostname"
I have a postfix on a server. When I'm trying to send an email from my python script, it gets rejected due to "Client host rejected: cannot find your hostname".
How to allow an email come through? If ...
- 1
1
vote
2
answers
223
views
Prevent using spam trap e-mail address on registration
I am running a website where the users register using their e-mail addresses and receive a confirmation code before they can log in. (After this every contact is opt-in.)
Every now and then some user ...
- 323
3
votes
1
answer
154
views
Sender Score Low
We host our own email server and have discovered we have a low sending score that is causing delivery issues. From the report (senderscore.org), there is an IP address outside of the U.S. (email ...
- 143
1
vote
0
answers
391
views
Backscatter relay from Postfix backup mx server causing spam (553 5.7.1)
I have 2 Postfix Servers
MAIN.mail.example.com
BACKUP.mail.example.com
Problem scenario:
If spammer sends email from "me" to me directly to BACKUP, server forwards it to MAIN
MAIN server reject ...
0
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1
answer
1k
views
SMTP Server All Records OK But All Email Sent in Spam
i bought a VPS with dedicated IP address and running windows Server 2012.
I installed an SMTP server and DNS server, created all needed records: SPF, DMARC, DKIM, PTR, MX, and A.
These results test ...
-2
votes
2
answers
3k
views
"My domain" is being recognized as spammer for "no reason" [closed]
I linked my brand new domain, to yandex.connectand I sent only a few test emails, but NO email was sent or received.
I checked many times the DNSs and they seem to be fine,
When I send emails from ...
- 121
0
votes
0
answers
102
views
Avoiding E-Mail spam filters (possibly based on originating computer?)
We recently started to send out a higher amount of E-Mails (invitations to a private event) to a select number of people.
Now from some of those people using office365 for Mails, we were informed that ...
0
votes
2
answers
1k
views
Can a DMARC "reject" policy prevent NDR backscatter?
Our email is being spoofed. We already have SPF/DKIM/DMARC p="quarantine" policies in place however we are still receiving thousands of Non-Delivery Receipt (NDR) in our inbox.
Will changing to DMARC ...
- 531
1
vote
0
answers
4k
views
Our email server is spammed with "Returned mail: see transcript for details"
We are running a fairly popular online service and since this morning our email inbox is spammed with emails like this "Returned mail: see transcript for details" by "MAILER-DAEMON@localhost....
- 27