case-insensitive handling of email addresses in signingtable

[chillout2k]

Email addresses should be handled case-insensitive:

LOCALPART@example.com      /path/to/key.pem

is currently not the same as:

localpart@example.com      /path/to/key.pem

Thanks in advance ;)

[andreasschulze]

https://tools.ietf.org/html/rfc5321#section-2.4 state explicit that LOCALPART@example.com is not necessarily the same as localpart@example.com. But that's not the expectation of today's email users.

I consider implementing a switch so you could treat local parts as case-insensitive in your environment.