Bug#1019959: Restore config macro to send >998 length lines

[Ian Kelling]

Package: exim4-config
Version: 4.95

exim4-config 4.95~RC0-1 removed IGNORE_SMTP_LINE_LENGTH_LIMIT which when
set, fully removed any line length limit. It was replaced with
IGNORE_SMTP_LINE_LENGTH_LIMIT which would accept mail with >998 length
lines, but not send them.

Please restore IGNORE_SMTP_LINE_LENGTH_LIMIT, or something similar, so
people don't have to overwrite Debian's smtp transports with ones that
add message_linelength_limit. That option doesn't have a documented max
or a way to say no limit, so I suggest 2^31. A 2GB line is effectively
turning off any limit.

Why?

Accepting >998 but not sending them breaks various useful things:

* Forwarding email with long lines doesn't work. I've also found
forwarded bounces bounce, even though bounce_return_linesize_limit
suggests they should be truncated.

* Every week I get legitimate patches >998 length on the GNU mailing
lists. The kernel linux has 20 text files with >998 lines. Exim itself
has 37 files. The only really popular tool I know for sending email
patches is git-send-email and it has no way to wrap those lines. It
seems a bit silly/ironic to ship a bunch of macros so that the core
config files don't need to be changed for typical uses, but not support
email patches for parts of exim itself.

-- 
Ian Kelling | Senior Systems Administrator, Free Software Foundation
GPG Key: B125 F60B 7B28 7FF6 A2B7  DF8F 170A F0E2 9542 95DF
https://fsf.org | https://gnu.org