8
votes
How to send emails and avoid them being classified as spam?
Detailed solution to avoid emails to be identified as spam and/or not arriving to receivers
Example situation: You have a server running a PHP website for example.com that needs to send emails. And ...
- 739
5
votes
Improve Spam Confidence Level (SCL) for outgoing emails
Here's what helped me:
Make sure that SPF and DomainKeys / DKIM are setup and working (DMARC might help you)
Try disabling IPv6 when sending mail (I had the problem with postfix that the HELO headers ...
- 171
5
votes
Accepted
DMARC record is valid, but your domain's None/Quarantine policy does not yet protect it against email spoofing and phishing
It is not an error, but a common step while working towards stronger methods of protecting against spoofing. The warning reminds you that your published record, while still useful to opt into ...
- 9,783
4
votes
Spam passing postfix config "hostname does not resolve to address: No address associated with hostname"
From #postfix@freenode IRC, I've gotten the helpful hint (thanks, JPT) that the connecting IP/hostname is, of course, checked in smtpd_client_restrictions.
smtpd_client_restrictions =
[...]
...
- 359
3
votes
Accepted
TXT entry in DNS for both gmail and amazon ses
Using ~all means that mail will come from the servers listed in the SPF record, but may also come other sources. However, by just specifying the Google record some mailers could be more wary of your ...
- 5,391
3
votes
Postfix reverse MX check
Postfix can't do this. I use rspamd for that, there is a rules:
MX MX_INVALID Domain has no working MX
MX MX_MISSING Domain has no resolvable MX
Just set high score and enjoy blocking spam.
p....
- 31
3
votes
Accepted
What is DNS TXT record "mailru-verification"?
It's domain verification for service PostMaster.mail.ru.
There you can get some statistics about your letters delivery, spam, problems, configure feedback loop and so on.
Quite handsome.
If you have ...
- 156
3
votes
What is DNS TXT record "mailru-verification"?
I suspect it's used for domain ownership verification when signing up for some SaaS-style service where you're allowed to use your own domain name.
This is fairly common practice to thwart abuse, and ...
- 35.5k
3
votes
How to send emails and avoid them being classified as spam?
There's a new guide that's been published on email Inboxing
The most comprehensive I ever seen. A checklist of 43 different points that cover every faucet of how to avoid being marked as spam. That's ...
- 940
3
votes
Using a subdomain for email address
The spam filters questions is a very large one and really depends on the content of the messages. What I think you are really asking it whether the connection from your mail server will be accepted ...
2
votes
Exchange 2010 ignoring SPF record
If your Exchange server is honoring SPF records for other domains but not yours, then you probably have your internal DNS set to be authoritative for your domain name, but you don't have the SPF ...
- 23.2k
2
votes
Exchange office 365 transport rules to block spam when FROM doesn't match smtp.mailfrom or return path
The mismatch between Return-Path (envelope sender) and From: doesn't necessarily indicate spam and shouldn't be used as an explicit rule for blocking any messages.
For example we could have a ...
- 49.8k
2
votes
Accepted
Postfix - Send spam to different email address
Postfix can check the headers set by the milter with milter_header_check. The postfix documentation also provides an example:
The following example sends all mail that is marked as SPAM to a spam ...
- 226
2
votes
Accepted
body_checks: How to filter base64 encoded content?
There is a builtin feature for diagnosing postfix map lookups, specifically for body_checks as well. Pass the same map configuration you configured for your smtpd cleanup service to the postmap ...
- 9,783
2
votes
Accepted
Postfix no longer rejecting emails based on spam block lists
So, although dig requests (e.g.dig @localhost a 185.176.220.75.zen.spamhaus.org) were returning expected results, leading me to assume there was no network/DNS issue, I did find in my OpenDNS ...
- 331
2
votes
Accepted
How to minimize chances of one's domain being falsely blacklisted (uribl)
How to minimize chances of one's domain being falsely blacklisted?
Put your org name and preferred methods of contacts wherever one might look. Setting up a web server for all domains you are sending ...
- 9,783
2
votes
Is an email server that accepts an email and then silently filters it out complying with SMTP standards?
I highly recommend to think of this less of an exercise in maximizing compliance, but more in a exercise in minimizing the disservice to humans having to suffer the collateral damage.
The relevant ...
- 9,783
1
vote
How to whitelist our own outgoing emails from being blocked in amavis/spamassassin using Spamhaus' block lists?
After much fiddling and reading around I read something somewhere about order being important in smtpd_client_restrictions, so I thought, maybe these "reject" directives related to ...
- 179
1
vote
Accepted
Any way to bypass Barracuda spam filter for specific addresses?
Log in to your Barracuda Cloud Control. Go to Email Security >
Inbound Settings > IP Address Policies.
In the IP Blocking /
Exemption section, use the top line to enter the IP addresses.
This ...
- 736
1
vote
Accepted
Postfix - Eliminate sender domain based on recipient email address
Don't do that, there are entire organizations (Spamhaus would be a notable one) that do this on a better scale, with better handling of edge cases, and with easier remediation in case it hits senders ...
- 9,783
1
vote
Postfix's header checks not working as expected
You need to not use the flag "i" to make it case insensitive indeed. From the manual, https://www.postfix.org/regexp_table.5.html:
i (default: on)
Toggles the case ...
- 231
1
vote
Gmail detects emails as spam from domain with neutral reputation
Its very simple you got an IP reputation which is based on how and when do you things send. Google rejects your mails because something is clearly missing.
The current requirements are tls encrypted ...
- 111
1
vote
Accepted
Can I disable spam filtering for one user in Exchange Online Protecttion?
“Is it possible to disable the spam filtering for one user only?” This user is in your organization or external user?
Every organization has a built-in anti-spam policy named Default, it is applied to ...
- 824
1
vote
Incoming Email Server (I think) is Blocking Email Form
Troubleshooting is really just common sense. (First, is this only happening with some clients? If so is anything different with their websites? If it's only a few and the sites are cookie cutter then ...
- 313
1
vote
Accepted
Unknown ACL condition/modifier in in EXIM configuration for Rspamd
Place spamd_address = 127.0.0.1 11333 variant=rspamd directive outside the ACL section. In general it should be placed at the beginning of config before ACLs, services, routers and transports are ...
- 7,034
1
vote
filtering spam emails with Chinese subject
You should block all IPs found in https://intodns.com/qq.com
Here is the list of IPs I have blocked, but you should check every now and then because IPs keep getting changed/added:
101.226.68.138
14....
- 11
1
vote
How to block SendGrid spam with sendmail?
For the record, I share similar opinions that MailChimp and SendGrid themselves aren't necessarily bad (although they certainly could have bad customers that they don't know about).
Opinion aside, ...
- 12k
1
vote
Exchange 2013 - Remove warning text from outgoing email body
There is no such rule. The MS Exchange transport rules can only add such a string but couldn´t remove them.
I would do the following:
Setup a Proxy (Squid and SquidGuard or something like that)
...
- 2,888
1
vote
What is DNS TXT record "mailru-verification"?
TXT records are kind of a description for the entry. One can write whatever he wants in these entries. This is mostly for internal use and does not affect the ip/name resolution.
See also: en....
- 1,218
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