[OpenIndiana-discuss] sendmail single user host sending to internet thru Smarthost: examples

[Hugh McIntyre]

Harry,

It looks like you've asked about sendmail several times before.  Did you 
previously have a working config, but changing to Comcast broke things? 
Or changing to a new domain name for email, etc.?

In terms of sendmail, I personally switched to postfix a few years ago 
so I can't provide a working config.  Jonathan's pointer below is 
probably good although I used to use a much smaller list of settings.

But I would make two comments:

1. Comcast blocks outgoing connections to port 25 to control spam, so if 
you are using SMART_HOST you will also need to use one of the submission 
ports, not port 25.  The port numbers are 465 if using SSL, or 587 if 
not. See 
http://customer.comcast.com/help-and-support/internet/email-port-25-no-longer-supported/. 
  I'm not sure how to configure this in sendmail, but see the 
RELAY_MAILER/RELAY_MAILER_ARGS comment below.

2. When submitting mail to the smart_host, your copy of sendmail will 
need to authenticate.  Generally this will be with the same 
username/password you would use to configure sending mail in 
Thunderbird, enabled via SASL (although sendmail may have a different 
way of enabling this).  It's also possible to use client certificates if 
you control the remote mail server -  John Beck had an old blog post 
describing how to enable this for sendmail - but most commercial 
providers expect username/password so you need to enable this.

I know how to do this for postfix, but not sendmail any more.  Partly 
because the Solaris sendmail historically did not come with SASL 
support, so this needed to be compiled in which was a PITA.  However you 
could try searching google for "sendmail smart_host submission port" -- 
it looks like the SMART_HOST line may need to change to:

define(`SMART_HOST',`relay.example.com`)dnl
define(`RELAY_MAILER',`esmtp')dnl
define(`RELAY_MAILER_ARGS', `TCP $h 587')dnl

See 
https://unix.stackexchange.com/questions/132711/using-port-587-with-sendmail 
or https://access.redhat.com/solutions/60803 (this also discusses 
username/password setup), or other search results.

Hugh.



On 8/23/17 1:41 AM, Jonathan Adams wrote:
> if you don't have a resolvable domain, you might well have issues with
> receiving the emails at the other end ...
> 
> if you're using a smart-host you might not have this trouble, but if you're
> not able to reverse lookup your IP address your email will be rejected by
> the remote host.
> 
> segments from my sendmail.mc, not that I use sendmail any more since the
> company took the decision to move to office365 ...
> 
> VERSIONID(`@(#)main-v7sun.mc    1.2 (Sun) 01/27/98')
> OSTYPE(solaris2.ml)dnl
> DOMAIN(solaris-generic)dnl
> MASQUERADE_AS(domain.com)
> FEATURE(masquerade_envelope)dnl
> FEATURE(masquerade_entire_domain)dnl
> MASQUERADE_DOMAIN(domain.com)
> 
> FEATURE(`nocanonify')
> FEATURE(use_cw_file)
> 
> FEATURE(`access_db')
> # to create /etc/mail/access.db (for allowed local hosts) do 'makemap hash
> /etc/mail/access < /etc/mail/sendmail.access'
> 
> define(`confPRIVACY_FLAGS',
> `authwarnings,restrictqrun,noreceipts,noexpn,novrfy,noetrn')dnl
> define(`confDONT_PRUNE_ROUTES', `True')dnl
> define(`confCOPY_ERRORS_TO', `postmaster')dnl
> define(`confSEPARATE_PROC', `True')dnl
> define(`confQUEUE_SORT_ORDER', `time')dnl
> 
> define(`confMIN_QUEUE_AGE', `30m')dnl
> define(`confTO_QUEUERETURN', `2d')dnl
> define(`confTO_QUEUERETURN_URGENT', `4h')dnl
> 
> define(`SMART_HOST', `[salmon190-19]')dnl
> define(`confDOMAIN_NAME', `domain.com')
> MAILER(local)dnl
> MAILER(smtp)dnl
> 
> 
> On 22 August 2017 at 20:48, Harry Putnam <reader at newsguy.com> wrote:
> 
>> Can anyone here show a working example of sendmail setup for single
>> user HOST sending mail out by relay to a `smarthost'
>>
>> More explicitly, the host has no REAL domain name just a made up domain
>> of the home lan, not resolvable from internet.
>>
>> I would guess such a host would be doing something with
>> `genericstable', or `masquerading' of a resolovable domain or maybe
>> both.
>>
>> My internet provider is comcast and far as I know, short of a
>> commercial contract, do not give there users home hosts domain names,
>> but a dynamic IP.
>>
>> I'd really like to see a working setup example of sendmail.mc for a
>> similar kind of setup as I've described.
>>
>>
>> _______________________________________________
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>> openindiana-discuss at openindiana.org
>> https://openindiana.org/mailman/listinfo/openindiana-discuss
>>
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