Hot answers tagged

42 votes

sendmail can not deliver to gmail - IPv6 sending guidelines regarding PTR records not met

Check the current protocols: postconf inet_protocols net_protocols = all Edit cf File if it returns all grep 'inet_protocols' /etc/postfix/main.cf inet_protocols = ipv4 Restart service postfix ...
Ender's user avatar
  • 624
20 votes
Accepted

Postfix - gmail encryption

You are missing the smtp_tls_security_level directive. smtp_tls_security_level = may This will set it to opportunistic TLS, using encrypted connections if the server supports it, but allowing ...
Gerald Schneider's user avatar
19 votes

how to fix "send-mail: Authorization failed 534 5.7.14 "

This worked for me. 1) Login to your gmail account. 2) Go to https://www.google.com/settings/security/lesssecureapps and Turn On this feature. 3) Go to https://accounts.google.com/...
user329161's user avatar
14 votes
Accepted

Why don't my domain's messages to a google group get their headers rewritten so DMARC can pass?

I did finally get this response from Google. I was glad to find someone who understood the issue, but unfortunately it looks like Google is sticking with their incorrect treatment of the DMARC ...
lordbyron's user avatar
  • 371
14 votes

How can the `to:` and `delivered-to:` fields in an email i received be different?

Just like snail mail letters, SMTP email has two different sets of address information: the envelope headers (like the addresses printed on the outside of an envelope) which are used by the SMTP ...
HBruijn's user avatar
  • 80k
13 votes
Accepted

Postfix - Untrusted TLS connection

Is there an easy way to gain a Trusted TLS connection instead of untrusted, do I need to buy something or this free certificate should work? This is not about your certificate, so you don't need to ...
gxx's user avatar
  • 5,651
12 votes

Why doesn't "dig gmail.com mx" return the domain "smtp.gmail.com"?

How about the smtp.gmail.com, why isn't it included? Because smtp.gmail.com doesn't receive email for the gmail.com domain. You asked for the MX record for gmail.com. The answer you got was exactly ...
joeqwerty's user avatar
  • 111k
11 votes
Accepted

Gmail flagging Dovecot email as insecure

I solved this by adding both these lines to Postfix's main.cf: smtp_tls_security_level = may smtpd_tls_security_level = may (I had only set smtpd_tls_security_level because of a misleading article ...
gavanon's user avatar
  • 529
10 votes
Accepted

Mail from Teams forwarded to Gmail marked as spam due to DMARC failure

I would assume its Microsofts fault for breaking their signature. The headers clearly say that the signature was good before forwarding, and then broken on receipt by Google. Checking the signed ...
anx's user avatar
  • 9,649
9 votes
Accepted

Why does DMARC operate on the From-address, and not the envelope sender (Return-Path)?

Think of SPF and DKIM as ways to validate the mail path, and think of DMARC as an extension that also validates the message sender. Think of this as delivering a FedEx letter. It's easy to validate ...
GuitarPicker's user avatar
9 votes

Why doesn't "dig gmail.com mx" return the domain "smtp.gmail.com"?

As joeqwerty rightly points out, it doesn't show smtp.google.com because a MX record indicates where mail servers should send messages destined for that domain. This is not the same as the servers ...
Andrew B's user avatar
  • 33k
9 votes

Why doesn't "dig gmail.com mx" return the domain "smtp.gmail.com"?

My initial goal is find all smtp servers of an email provider. You can't.
Wesley's user avatar
  • 32.8k
8 votes

Amazon SES instead of Gmail for company email

SES is not designed for this - SES is primarily for automated sending email, with the facility to receive email and send it to automated systems via Lambda, SNS, or stored on S3. Sending would ...
Tim's user avatar
  • 32.6k
7 votes

Gmail flagging Dovecot email as insecure

Your email is sent unencrypted. If you just want to try your best add the following to your main.cf smtp_tls_security_level = may To enforce TLS encryption for email sent to google add this to your ...
Jofre's user avatar
  • 559
7 votes

When DKIM is installed, will I still be able to send email for my domain from gmail?

DomainKeys Identified Mail (DKIM) is for ensuring that mail content hasn't tampered during transmission. Unlike Sender Policy Framework (SPF) it's not trying to validate the source of the message as ...
Esa Jokinen's user avatar
  • 49.5k
6 votes

How to check if a mail server is flagged as SPAM by GMail?

Go to http://postmaster.google.com/ and sign up there, this is recommended by Google https://support.google.com/mail/answer/188131 for blocked emails. Google provides you there with your individual ...
Thomas's user avatar
  • 411
6 votes

How to send a mail with a URL with swaks?

The email without the mime headers would come across as plain text. The mime headers make the message body gets seen as HTML. swaks --body '<a href="https://en.wikipedia.org/wiki/Main_Page">...
user123456's user avatar
6 votes

postfix: Cannot assign requested address

The delivery attempt on the second log excerpt tries to use IPv6 and after failing, falls back to IPv4 and delivers the message successfully. You can either fix your IPv6 host configuration if you ...
AlexD's user avatar
  • 10k
6 votes

Is ed25519 well supported for the DKIM validation?

As of 2022-01, not a single big mail provider regularly verifies ed25519 signatures, though the reported result will not be consistent, I have seen in DMARC reports (along with pass for other ...
anx's user avatar
  • 9,649
6 votes
Accepted

Gmail does not accept mail from a new VPS server with PTR setup

Your PTR record for IPv6 is setup correctly (and strictly speaking it seems to be no longer required by Gmail). Saying that one hint is in the message Gmail sends to you: or the corresponding forward ...
Tomek's user avatar
  • 3,553
5 votes

monit send email does not work

You can use a remote mail server. Here are my sample configs which worked. It sends alerts to my gmail through a remote smtp server. I think you still use Gmail as an smtp relay as well. #configure ...
David Okwii's user avatar
5 votes

Why does DMARC operate on the From-address, and not the envelope sender (Return-Path)?

There are two "why" questions: Why does a receiving mail server perform the check in this manner because that's what section 3.1 of RFC 7489 says to do Why was DMARC designed that way? ...
Martin Kealey's user avatar
5 votes

Gmail flagging Dovecot email as insecure

Consider the client/server relationship with regards to SMTP and the settings make sense: 2.1. Basic Structure The SMTP design can be pictured as: +----------+ +-------...
user885983's user avatar
5 votes

Postfix can send mails to all domains except gmail

You seem to be using SMTP port 25 for both incoming and outgoing mail. Because you have smtp inet n - - - - smtpd -o content_filter=spamassassin spamassassin unix - n n - ...
Esa Jokinen's user avatar
  • 49.5k
5 votes
Accepted

Postfix smtp relay quota and configuration for Google Suite (Gmail)

I finally discovered that G-Suite has a documentation article for this exact question. Depending on your requirements, the available options are: G Suite SMTP relay service — Send mail from your ...
maxime_039's user avatar
5 votes

Somebody bought my old domain and I can't access my old mail

"I don't have access anymore to the email account that was used to sign up" is not a rare occurrence. People commonly use their work email and will lose access to that once their ...
Bob's user avatar
  • 5,963
5 votes

Two mail providers for the same domain

you cant have two different providers for the same exact domain, but you can have a different subdomain for some emails. you could have the important email at google , for [email protected] , ...
neofutur's user avatar
  • 675
4 votes

Cannot send email from EC2 instance on port 587

For send an email from AWS EC2 using Gmail SMTP service please follow below steps. Edit security group of your EC2 Instance. Edit inbound rules of the security group. Add 587 port in inbound rules. ...
Krupal Patel's user avatar
4 votes

Remove "via" from emails sent to Gmail from Amazon SES

If your 'from' description contains certain special characters it can fail even with everything set up correctly. eg. having a registered trademark in my 'from' screwed everything up var toAddress = ...
Simon's user avatar
  • 1,381
4 votes

Can you configure MS Exchange to support the gmail "+keyword" trick?

This feature is now available on Office 365 Exchange! Exchange admins will have to enable this manually on their server. This can be done through Powershell using the following command: Set-...
AutoBaker's user avatar
  • 188

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