GNU Mailutils

2.3 SMTP Mailboxes

SMTP mailboxes types are special remote mailboxes that allow only append operation. Appending a message is equivalent to sending it to the given recipient or recipients.

smtp

A remote mailbox accessed using the Simple Message Transfer Protocol.

The SMTP URL syntax is:

smtp://[user[:pass][;auth=mech,...]@]host[:port][;params]

The host gives the name or IP address of the host running SMTP server. Optional port can be used to connect to a port other than the default 25.

The user, pass, and ‘auth=’ elements supply credentials for ESMTP authentication, if the server supports it.

If the ESMTP authentication is used, Mailutils will select the best authentication mechanism from the list offered by the server. To force it to use a particular authentication mechanism, use the ‘auth’ authentication parameter. Its value is a comma-separated list of authentication mechanisms, in the order from the most to the least preferred one, e.g.:

smtp://smith:guessme;auth=cram-md5,digest-md5@localhost

Optional params is a semicolon-separated list of additional parameters. Valid parameters are:

auth=mechlist

Same as the auth parameter used in credentials part. See above for a discussion.

domain=string

Append ‘@string’ to those recipient addresses that lack the domain part.

ehlo=host

Sets hostname to be used as argument to the SMTP EHLO command. Default is to use current hostname.

from=addr

Use addr as sender address.

noauth

Disable ESMTP authentication.

notls

Disable TLS.

read-recipients

Read recipients from the message headers, even if to parameter is also given. In the latter case, the effective list of recipients is constructed by appending addresses obtained from the message to the list of addresses from the to parameter.

The headers from which recipient addresses will be read are ‘To’, ‘Cc’, and ‘Bcc’. This list can be modified using the recipient-headers parameter.

recipient-headers[=name[,name...]]

Use the supplied header names to determine recipient addresses, instead of the default ‘To’, ‘Cc’, ‘Bcc’. These headers will be consulted if no explicit recipient is supplied using the to parameter, or if the read-recipients parameter is specified.

If no values are supplied, this parameter disables header scanning. In this case recipients must be supplied explicitly (see to parameter below).

strip-domain

Strip domain part from all recipient addresses. This is intended to be used together with domain (see above).

to=addr[,addr...]

Deliver messages to the supplied email addresses.

smtps

A remote mailbox accessed using the Simple Message Transfer Protocol, with the transmission channel encrypted using the transport layer security (TLS). The default port is 465.

The URL is

smtps://[user[:pass][;auth=mech,...]@]host[:port][;params]

See the ‘smtp’ type for a detailed description of its types. The only difference from ‘smtp’ is that the ‘notls’ parameter is not used.