45.5 Header verification Exim's sender verification options can be used to block messages with bad envelope senders. If there are several occurrences of any of the relevant headers, they are all checked. This is a syntax check only. 45.6 Receiver verification By default, Exim just checks the syntax of addresses given in the SMTP RCPT command. This minimizes the time required for an SMTP message transfer, and also makes it possible to provide special processing for unknown local parts in local domains, by using a smartuser director to pass messages with unknown local parts to a script or to another host.
Some installations prefer to check receiver addresses as they are received.
Verification consists of running the directors and routers in verify mode. When verification fails, a permanent negative response is given to the RCPT command. Go to the first , previous , next , last section, table of contents .