Error while sending a mail from mutt

[Okash Khawaja]

> On 29 Mar 2017, at 21:19, Jim Davis <jim.epost at gmail.com> wrote:
> 
> On Wed, Mar 29, 2017 at 12:32 PM, AYAN KUMAR HALDER
> <ayankumarh at gmail.com> wrote:
>> Hi,
>> 
>> I am trying to send a mail using mutt. I am getting the error as follows :-
>> 
>> SMTP session failed: 501 5.5.4
>> 
>> I understand the error meant that a valid mail transaction protocol
>> was used with invalid arguments. Please let me know how do I debug
>> this issue further.
> 
> Mutt usually invokes some other program to send mail -- on my
> workstation, for instance, that other program is /usr/sbin/sendmail:
> 
> [jim at krebstar ~]$ mutt -v | grep '^SENDMAIL'
> SENDMAIL="/usr/sbin/sendmail"
> 
> so to debug a similar problem on my workstation I'd first look to see
> where sendmail (or whatever program your mutt installation uses) logs
> its messages.
> 
> That used to be in /var/log/maillog or such; nowadays you might have
> to run journalctl instead.
> 
> For example, if I try
> 
> mutt postmaster at example.com </dev/null
> 
> on my workstation, then
> 
> journalctl | grep sendmail
> 
> tells me
> 
> Mar 29 12:59:06 krebstar.arl.arizona.edu sendmail[27263]:
> v2TJx61J027263: to=postmaster at example.com, ctladdr=jim (1000/1000),
> delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30294,
> relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection
> refused by [127.0.0.1]
> 
> which reminds me I don't actually have the sendmail service running.

You can check ~/.muttrc file to see what it is using to send emails. If it is using sendmail or esmtp, then in .muttrc file where it specifies sending program you can append -X /path/to/log/file. That will output the whole SMTP dialog to that log file.