How do I support multiple ISP accounts (smarthost) in the Postfix SMTP client for relaying email? For example:
[a] user1@isp1.com must be relay via smtp.isp1.com.
[b] user1@isp2.com must be relay via smtp.isp2.com.
[c] me@mycorp.com must relay all my default email via smtp.mycorp.com.
Only Postfix version v2.3+ supports multiple ISP accounts via sender-dependent override for the global relayhost parameter settings. Open your main.cf file:
# vi /etc/postfix/main.cf
Add or modify the settings as follows:
smtp_sender_dependent_authentication = yes sender_dependent_relayhost_maps = hash:/etc/postfix/relayhost_map smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/passwd relayhost = [smtp.mycorp.com]:submission
Create /etc/postfix/relayhost_map file:
# vi /etc/postfix/relayhost_map
Append configuration as follows (please note that default smtp.mycorp.com is not included) :
# Per-sender provider user1@isp1.com [smtp.isp1.com] user1@isp2.com [smtp.isp2.com]
Create update /etc/postfix/passwd file as follows:
# Per-sender authentication
user1@isp1.com user1@isp1.com:password4isp1
user1@isp2.com user2@isp2.com:password4isp2
# Login for the default relayhost
[smtp.mycorp.com] defaultUsername:defaultPassword
Save and close the file. Restart Postfix:
# postmap hash:/etc/postfix/passwd
# postmap hash:/etc/postfix/relayhost_map
# /etc/init.d/postfix reload
Where,
- smtp_sender_dependent_authentication = yes : Enable sender-dependent authentication in the Postfix SMTP client; this is available only with SASL authentication.
- sender_dependent_relayhost_maps = hash:/etc/postfix/sender_relay : A sender-dependent override for the global relayhost parameter setting. The tables are searched by the envelope sender address and @domain. A lookup result of DUNNO terminates the search without overriding the global relayhost parameter setting.
- smtp_sasl_auth_enable = yes : Enable SASL authentication in the Postfix SMTP client. By default, the Postfix SMTP client uses no authentication.
- smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd : SMTP client lookup tables with one username:password entry per remote hostname or domain, or sender address when sender-dependent authentication is enabled.
- relayhost = [mail.myisp.net]:submission : Setup default relay host.
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- Last Updated: 03/13/09
{ 4 comments… read them below or add one }
Previous I was tried this concept but it was not working
My scenarios adding multiple users with SMTP auth
With username and passwd
Am waiting for your reply.please scrap me or mail me
this is my email id : krisuresh001@gmail.com
Is this also supported on sendmail?
At first, thanks aslot for making this (almost) clear.
What I don’t understand is: If …
“[a] user1@isp1.com must be relay via smtp.isp1.com.
[b] user1@isp2.com must be relay via smtp.isp2.com.”
(so there is only user1 involved)
… then why is this line in /etc/postfix/passwd ?
“user1@isp2.com user2@isp2.com:password4isp2″
Where does user2 coming from all the sudden?!
Shouldn’t it be like this
“user1@isp2.com user1@isp2.com:password4isp2″
or do you just want to show, that the username on the “real” isp2.com has not necessarily to correspondent with the “local” user1?
Thanks for answering,
Coschuetzer
Global internet providers aim is to provide access that is effortless to utilize. They provide access that is as fast as you absolutely need it to be, and will work with the system you have.