How do I enable SMTP Authentication?

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Question

How do I enable SMTP Authentication?

Answer

GMS supports 4 types of authenticated SMTP, PLAIN, LOGIN, MD5 and CRAM-MD5, these are settings are held in the SMTPAuth System Variable. All can be set to operate at the same time so as to given clients a choice as to what they use.

These options can be set under the Mail > Incoming > ESMTP page. Scroll down until you see the option "Allow AUTH logon" and select the options you wish to enable.

LOGIN and MD5 work in similar ways to the PASS and APOP mechanisms respectively of POP (except that all data is binhex encoded). Both require the client to logon to the server – i.e. the client must know a username and password.

The MD5 mechanism uses a unique string appended to the AUTH=MD5 line to encrypt the password info, whereas APOP uses a unique value generated in the server sign-on message to encrypt the password info.

The values for each of the options are:

  • SMTPAUTH=1 for LOGIN
  • SMTPAUTH=2 for MD5
  • SMTPAUTH=3 for CRAM-MD5
  • SMTPAUTH=4 for PLAIN

Multiple options are supported by using a space separated list of settings, for example setting the variable SMTPAUTH= 4 3 1 will enable PLAIN, CRAM-MD5 and LOGIN. However there is no need to set these manually as the GUI will set them all for you automatically.

The POST service can also authenticate to a remote server that supports such an option by setting a POSTAUTH System Variable. The options are the same as for SMTPAUTH.

See Also:

Keywords:Authentication authenticated SMTP AUTH ASMTP

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