mu4e supports27 autocompleting addresses when composing e-mail messages. mu4e uses the e-mail addresses from the messages you sent or received as the source for this. Address auto-completion is enabled by default; if you want to disable it for some reason, set mu4e-compose-complete-addresses to nil.
Emacs 24 also supports cycling through the alternatives. When there are more than 5 matching addresses, they are shown in a *Completions* buffer. Once the number of matches gets below this number, one is inserted in the address field and you can cycle through the alternatives using TAB.
If you have a lot of mail, especially from mailing lists and the like, there can be a lot of e-mail addresses, many of which may not be very useful when auto-completing. For this reason, mu4e attempts to limit the number of e-mail addresses in the completion pool by filtering out the ones that are not likely to be relevant. The following variables are available for tuning this:
mu4e-compose-complete-only-personal— when set to t, only consider addresses that were seen in personal messages — that is, messages in which one of my e-mail addresses was seen in one of the address fields. This is to exclude mailing list posts. You can define what is considered ‘my e-mail address’ using the --my-address parameter to mu init.
mu4e-compose-complete-only-after— only consider e-mail addresses last seen after some date. Parameter is a string, parseable by
org-parse-time-string. This excludes old e-mail addresses. The default is "2010-01-01", i.e., only consider e-mail addresses seen since the start of 2010.
mu4e-compose-complete-ignore-address-regexp— a regular expression to filter out other ‘junk’ e-mail addresses; defaults to “no-?reply”.
GNU Emacs 24.4 or higher is required