Added the option to have a `mailcap` file in `.config/mutt/`. This enables ease of changing what programs are used for viewing.

avoid line splitting.
the width option is set to 80 by default, increasing it will avoid breaking long links in two different lines

Add domains for uclive.ac.nz addresses.
These are undergrad (and maybe other) addresses for
the University of Canterbury (https://canterbury.ac.nz/).

add mac alternative domains
(@mac.com/@me.com)
these are legacy domains that
mac used to use which have been
merged into icloud

for more info see:

https://support.apple.com/en-us/HT201771
https://getmailspring.com/setup/access-mac-com-via-imap-smtp

also add ucsc.edu, which like the other uc's uses
google

Signed-off-by: Nicolas Serafini <serafini.nicolas@gmail.com>

These might need STARTTLS explicitly disabled in the msmtp config file though

possible email are:
- username@studenti.unitn.it
- username@ex-studenti.unitn.it
- username@alumni.unitn.it
- username@unitn.it

cloeses #577 #572

Erciyes University configuration is updated.

Add nixnet.email domains to domains.csv

the macro for sync all accounts uses 'mbsync -a' command, which
failed to run for users who have moved their ~/.mbsyncrc somewhere
else.

we should use mw -Y instead, which can detect the MBSYNCRC env