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TCP/IP-channel-specific options: ALLOW_RECIPIENTS_PER_TRANSACTION (integer)

This SMTP/LMTP server option set s a limit on the number of recipients allowed per message, and on the number of address verifications (VRFY: commands) permitted during a transaction. (Note that the count of actual recipients, RCPT TO:, is separate from the count of verifies, VRFY:; that is, VRFY:'s do not count against the RCPT TO: limit, nor do RCPT TO:'s count against the VRFY: limit; each is limited independently to the ALLOW_RECIPIENTS_PER_TRANSACTION value.) Any additional recipients will be rejected with a temporary error response to the RCPT TO: command:

451 4.5.3 Too many recipients specified 

Any additional address verification attempts will be rejected with a temporary error

451 4.5.2 Verification blocked; too many operations performed 

at the VRFY: line. The default is 128. (In iMS 5.2 and earlier, the default was no limit.) See also the recipientlimit and (in the case of SMTP) disconnectrecipientlimit channel options , and the ldap_recipientlimit and ldap_domain_attr_recipientlimit MTA options. Note that with any setting of ALLOW_RECIPIENTS_PER_TRANSACTION other than the maximum allowed integer (2147483647), the SMTP server will not allow multiple, comma-separated values on the RCPT TO: command line. (The LMTP server, in contrast, will always allow multiple, comma-separated values on the RCPT TO: command line --- though the MTA's LMTP client will not itself send such a RCPT TO command.)

Note also that, unlike a channel recipientlimit (which may be completely overridden on a per-user basis using the LDAP attribute named by the ldap_recipientlimit MTA option), the TCP/IP-channel-specific option ALLOW_RECIPIENTS_PER_TRANSACTION imposes a hard upper-limit, which other settings may only modify by imposing even stricter limits but may not ignore (increase).

See also: