1 MAILWRAPPER(1M) Maintenance Commands MAILWRAPPER(1M)
2
3 NAME
4 /usr/lib/mailwrapper - invoke appropriate MTA software based on
5 configuration file
6
7 SYNOPSIS
8 Special. See below.
9
10 DESCRIPTION
11 At one time, the only Mail Transfer Agent (MTA) software easily available
12 was sendmail(1M). As a result of this, most Mail User Agents (MUAs) such
13 as mail(1) had the path and calling conventions expected by sendmail(1M)
14 compiled in.
15
16 Times have changed, however. On a modern UNIX system, the administrator
17 may wish to use one of several available MTAs.
18
19 It would be difficult to modify all MUA software typically available on a
20 system, so most of the authors of alternative MTAs have written their
21 front end message submission programs so that they use the same calling
22 conventions as sendmail(1M) and may be put into place instead of
23 sendmail(1M) in /usr/lib/sendmail.
24
25 sendmail(1M) also typically has aliases named mailq(1) and newaliases(1M)
26 linked to it. The program knows to behave differently when its argv[0]
27 is "mailq" or "newaliases" and behaves appropriately. Typically,
28 replacement MTAs provide similar functionality, either through a program
29 that also switches behavior based on calling name, or through a set of
30 programs that provide similar functionality.
31
32 Although having drop-in replacements for sendmail(1M) helps in installing
33 alternative MTAs, it essentially makes the configuration of the system
34 depend on hand installing new programs in /usr. This leads to
35 configuration problems for many administrators, since they may wish to
36 install a new MTA without altering the system provided /usr. (This may
37 be, for example, to avoid having upgrade problems when a new version of
38 the system is installed over the old.) They may also have a shared /usr
39 among several machines, and may wish to avoid placing implicit
40 configuration information in a read-only /usr.
41
42 The /usr/lib/mailwrapper utility is designed to replace /usr/lib/sendmail
43 and to invoke an appropriate MTA instead of sendmail(1M) based on
44 configuration information placed in /etc/mailer.conf. This permits the
45 administrator to configure which MTA is to be invoked on the system at
46 run time.
47
48 Other configuration files may need to be altered when replacing
49 sendmail(1M).
50
51 EXIT STATUS
52 The /usr/lib/mailwrapper utility exits 0 on success, and >0 if an error
53 occurs.
54
55 DIAGNOSTICS
56 The /usr/lib/mailwrapper will print a diagnostic if its configuration
57 file is missing or malformed, or does not contain a mapping for the name
58 under which it was invoked.
59
60 SEE ALSO
61 mail(1), mailq(1), newaliases(1M), sendmail(1M), mailer.conf(4)
62
63 illumos August 7, 2006 illumos
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1 MAILWRAPPER(1M) Maintenance Commands MAILWRAPPER(1M)
2
3 NAME
4 mailwrapper - invoke appropriate MTA software based on configuration file
5
6 SYNOPSIS
7 Special. See below.
8
9 DESCRIPTION
10 At one time, the only Mail Transfer Agent (MTA) software easily available
11 was sendmail(1M). As a result of this, most Mail User Agents (MUAs) such
12 as mail(1) had the path and calling conventions expected by sendmail(1M)
13 compiled in.
14
15 Times have changed, however. On a modern UNIX system, the administrator
16 may wish to use one of several available MTAs.
17
18 It would be difficult to modify all MUA software typically available on a
19 system, so most of the authors of alternative MTAs have written their
20 front end message submission programs so that they use the same calling
21 conventions as sendmail(1M) and may be put into place instead of
22 sendmail(1M) in /usr/lib/sendmail.
23
24 sendmail(1M) also typically has aliases named mailq(1) and newaliases(1M)
25 linked to it. The program knows to behave differently when its argv[0]
26 is "mailq" or "newaliases" and behaves appropriately. Typically,
27 replacement MTAs provide similar functionality, either through a program
28 that also switches behavior based on calling name, or through a set of
29 programs that provide similar functionality.
30
31 Although having drop-in replacements for sendmail(1M) helps in installing
32 alternative MTAs, it essentially makes the configuration of the system
33 depend on hand installing new programs in /usr. This leads to
34 configuration problems for many administrators, since they may wish to
35 install a new MTA without altering the system provided /usr. (This may
36 be, for example, to avoid having upgrade problems when a new version of
37 the system is installed over the old.) They may also have a shared /usr
38 among several machines, and may wish to avoid placing implicit
39 configuration information in a read-only /usr.
40
41 The mailwrapper utility is designed to replace /usr/lib/sendmail and to
42 invoke an appropriate MTA instead of sendmail(1M) based on configuration
43 information placed in /etc/mailer.conf. This permits the administrator
44 to configure which MTA is to be invoked on the system at run time.
45
46 Other configuration files may need to be altered when replacing
47 sendmail(1M).
48
49 EXIT STATUS
50 The mailwrapper utility exits 0 on success, and >0 if an error occurs.
51
52 DIAGNOSTICS
53 The mailwrapper will print a diagnostic if its configuration file is
54 missing or malformed, or does not contain a mapping for the name under
55 which it was invoked.
56
57 SEE ALSO
58 mail(1), mailq(1), newaliases(1M), sendmail(1M), mailer.conf(4)
59
60 illumos August 20, 2019 illumos
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