Debian – Postfix as SMTP server for Gmail. (“Send mail as” google option)

debiangmailpostfixsmtpssl

I have a vps on ovh.com runing debian 7. I want to set up my gmail account to send, and recieve mail on (for example) myname@example.com address. I searched google for hours and couldn't find a solution to my problem. I need a tutorial on how to set it up.

I've already configured postfix to forward mails sent to myname@example.com using this guide.

I receive mails, but they're unencrypted. Gmail displays a warning saying that ip-xxx-xx-xx.net (ovh provided i guess) did not encrypt this message. It seems that i have tls not configured.

My domain is configured as it should (i think) – example.com MX pointing at mail.example.com and mail.example.com A pointing at myserverip.

I tried to add smtp server to google (send mail as) and it sees the server on port 25 (postfix default) but it displays error:

Authentication failed. Please check your username/password. [Server response: 535 5.7.8 Error: authentication failed: authentication failure code(535)

So i need a tutorial which will guide me on how to set up postfix as SMTP server that i can add to my gmail account, so i can send emails from gmail using my alias (myname.example.com), receive on this adress with encryption.

UPDATE

I changed something and it seems like there is some authentication error.
Google greets me with something like this :

Authentication failed. Please check your username/password.
[Server response: Unspecified Error (SENT_SECOND_EHLO): Smtp server does not advertise AUTH capability code(0) ]

Best Answer

Add the following lines to main.cf and restart the postfix

smtp_tls_security_level = may
smtp_tls_protocols = !SSLv2, !SSLv3
smtp_tls_mandatory_protocols = !SSLv2, !SSLv3
smtp_tls_mandatory_ciphers = high

For debugging you can use

smtp_tls_loglevel = 1

SASL Authentication Check List

Base on question and comments, sasl may not be setup correctly. Following check list is created base on Ubunut Guide provided in question.

Check file/etc/postfix/sasl/smtpd.conf, should be like following
```
pwcheck_method: saslauthd
mech_list: plain login
```

Check libsasl installed

dpkg -l | grep sasl

Should have the following (version number may differ)

ii  libsasl2-2           2.1.25.dfsg1-4    Cyrus SASL - authentication abstraction library
ii  libsasl2-modules     2.1.25.dfsg1-4    Cyrus SASL - pluggable authentication modules
ii  sasl2-bin            2.1.25.dfsg1-4    Cyrus SASL - administration programs for SASL users database

Check saslauthd is running
```
ps -ef | grep sasl
```

Check saslauthd PWDIR

grep PWDIR /etc/default/saslauthd

Output should be

PWDIR="/var/spool/postfix/var/run/saslauthd"

Postfix submission/587

/etc/postfix/master.cf

The Ubuntu guide only un-comment one line

submission inet n       -       -       -       -       smtpd

Try ucomment the whole section, including the options following it

submission inet n       -       -       -       -       smtpd
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING

Then restart postfix

sudo service postfix restart

Double check your smtp login name

Since the guide is not using virtual user, your smtp login name should be joe only, not joe@mysite.com. Double check email clients on your deivces/computers/webservices(gmail) are NOT using your email address as smtp login name. (Many do that for you. You will have to manually change it if so.)
Remove Password Map

I believe you are authenticating against local Linux account, not virtual user. Remove the following lines in /etc/postfix/main.cf
```
# password maps will not work. Customer must provide credentials
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
```

Best Answer

Related Solutions

Ubuntu – Postfix on Ubuntu Server 9.10 can’t send mail to Gmail addresses

Can’t connect to SMTP over 587

SASL Authentication Check List

Postfix submission/587

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