Fix lmtp_save_to_detail_mailbox to be case insensitive?

[Daniel Lange]

Am 22.05.22 um 11:33 schrieb Lucas Rolff:
> Wouldn’t it be ideal to link to a LMTP documentation page that describes how to do the same thing under LTMP, and not link to LDA?

No, because that's not (easily) possible as others have pointed out 
already. FTR: It is possible but on the postfix side of things with 
multiple options. 
https://groups.google.com/g/mailing.postfix.users/c/1p0ubY726N8/m/D3s9V5PXHcIJ 
for the oldest solution I could find.

There is no need to use LMTP if people want to use +extension addressing 
in their small setups.