Sending date in uppercase in "SINCE {0}" clause is against RFC3501 and fails on at least one IMAP server.

[michael-shipaev]

Hello,
We on our project stumbled upon using ImapFolder.Search(SearchQuery.DeliveredAfter(date)) method.
Constantly getting "UID SEARCH Backend error" response from imap server.
After investigating the issue I found that there is a ImapFolder.FormatDateTime method that converts date representation to uppercase. Removing the conversion fixed the issue.
I wonder if this conversion is there for purpose (perhaps the things are vice-versa in some other IMAP server implementations that expect uppercase dates only)?
Anyway the RFC3501 specifies that the month names in a date represenation must start with first capital letter the rest are lower-case (e.g. Jan, Feb, etc.)
So if the currently applied uppercase convertion is not a compatibility measure it would be good to change it to comply with RFC since definetly there are IMAP servers that expect dates strictly in RFC3501 format.

[jstedfast]

Thanks for the bug report. It is now fixed in git master.