Editing Fetchmail (section)

==In multidrop-mode==

fetchmail assumes that the mail server account actually contains mail intended for any number of different recipients. Therefore, fetchmail must attempt to deduce the proper "envelope recipient" from the mail headers of each message. In this mode of operation, fetchmail almost resembles a mail transfer agent (MTA). 
Note that neither the POP nor IMAP protocols were intended for use in this fashion, and hence envelope information is often not directly available. The ISP must stores the envelope information in some message header and. The ISP must also store one copy of the message per recipient. If either of the conditions is not fulfilled, this process is unreliable, because fetchmail must then resort to guessing the true envelope recipient(s) of a message. This usually fails for mailing list messages and Bcc:d mail, or mail for multiple recipients in your domain. 
fetchmail uses multidrop-mode when more than one local user and/or a wildcard is specified for a particular server account in the configuration file.