GoDaddy VPS – Can’t Connect to GoDaddy VPS SMTP Server

godaddysmtpvps

I have an ASP.Net C# web application which sends out email notification. I configured it to use the SMTP server on our VPS to send the email. But if the application is not hosted on the VPS I get an error. The innermost exception message says:

A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond xxx.xxx.xx.xxx:xx

If the application is hosted on the VPS, it works just fine.

I checked if the port is open on yougetsignal.com and it says port 25 is open. But using telnet (on my local machine) it says: Could not open connection to the host, on port 25: Connect failed. I also tried portchecktool.com on the VPS and it says Your ISP/Router/Firewall is not blocking port 25.

I have no idea what to do, can you help me out?

Best Answer

As you are using this SMTP server for outgoing mail, configure authenticated Message Submission (RFC 6409) to port 587 with STARTTLS (or SMTPS to port 465). You should be able to use this from almost anywhere where the SMTP port 25 is blocked because the connection is not intended to be used for hosting a mail server. This doesn't affect SMTP connections out from your VPS.

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

Windows Server 2008, can’t connect on local SMTP Server into localhost

Can’t connect to SMTP over 587

SASL Authentication Check List

Postfix submission/587

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