Command Maps to:
	+mail @mail 
	+skim @mail 
	+read @mail 
	+delete @mail/clear 
	+undelete @mail/unclear 
	+flush @mail/purge 
	+toss @mail/abort 
	+tag @mail/tag 
	+untag @mail/untag 
	+send @mail/send 
	+mail/quick @mail/quick 
	+cc @mail/cc 
	+proof @mail/proof 
	+safe @mail/safe 
	+bounce @mail/fwd 
	+forward @mail/fwd 
	+reply @mail/reply/quote 
	+replyall @mail/replyall/quote

+old[un]delete [<range>]
+oldflush

If your mail option is set to 'hard delete', +delete will delete the mail messages. If your mail option is set to 'soft delete', then messages are merely marked for deletion and +flush is required to remove them. If no <range> is specified, the current message is used. Although generally deletion is irretrievable, if you originally sent the message and have deleted your copy you may be able to +review the message, provided at least one copy remains amongst the recipients.

If a player has more saved messages in his mailbox than the quotas permit, he will not be able to send new +mail until he is below the +mail quota. He will also be given a large annoying message when he connects, warning him that he is over the +mail quota.

In general, the MUSH database should not be used to store large amount of +mail; the +dumpmail command is provided for the archival of messages that one needs to keep. This method of enforcement prevents players from sending mail, rather than receiving it, because having mail messages fail because of a quota tends to be more of an annoyance to the sender than to the recipient; it is intended to provide a strong prod to clean up one's +mail, rather than absolutely prevent large mailboxes.

The command '+set mail quota <player>=<unread>/<read>' permits a wizard to change the amount of +mail quota that a player has available. The defaults for quotas are given by '+mail defaults'; personal quotas are given by '+mail status'.

<range> can be one of the following:
<number> Just that number, i.e., "5" for message #5.
<list of numbers> Several numbers, i.e., "3 8" for messages #3 and #8.
<range of numbers> A range of numbers, i.e., "2-5" for messages #2 to #5.
all All messages.
current The current message.
deleted Messages marked for deletion.
last[:<num>] The last (or last <num>) message(s).
marked Marked messages.
next The message after the current message.
previous The message before the current message.
unread Messages that are unread.
author:<name> Messages from <name>.
subject:<string> Messages with <string> somewhere in the subject line.
tag:<string> Messages tagged with <string>.
text:<string> Messages with <string> somewhere in the message body.
For keywords, only the first letter needs to be specified.

+oldread [<range>]
+skim [<range>]
+mailstatus <character1> <character2> ...
+olddumpmail <range>

These commands should be fairly intuitive.
The +read command with no argument reports the number of read and unread messages in your mailbox, and is a useful command to put in your @aconnect.
+mailstatus reports any unread mail for a space-separated list of characters, such as your alts.
+dumpmail dumps your mailbox in a basic text format to screen for logging.
+help ranges for more information about specifying <range>

+oldreview letters [<list>]
+review letter [<list>]
+retract letter <number>

The first form of the +oldreview command summarises letters you have sent, and the second form reads them longform, according to <list>.
<list> can contain a list or range of numbers, the keywords 'all' (all letters), 'last' (last letter), 'last:<number>' (last <number> letters), 'to:<name>' (searches To, Cc, Bcc fields for that recipient or alias), 'subject:<pattern>' (looks for <pattern> in subjects), or 'text:<pattern>' (looks for <pattern> in letter text). For example,
> +review letters to:Richard

+mail may be +retracted if it has not yet been read by any of its recipients, or if it is older than its Expiration time.