HP-UX Mailing Services Administrator's Guide

Configuring and Administering Sendmail
Modifying the Default Sendmail Configuration File
Chapter 2 51
2. Set the value of the option MaxHeadersLength=n, where n is the
maximum number of lines allowed in the mail header.
If a mail header exceeds the maximum value, the following error
message is displayed to the sender:
552 Headers too larger #MaxHeadersLength
Limiting Message Recipients
By default, the maximum number of recipients is 100. You can limit the
number of users allowed to receive a single mail message. This helps to
prevent the flow of spam on the mail server.
•In the sendmail.cf file, set the value of
MaxRecipientsPerMessage=n, where n is the maximum number of
recipients allowed for a single mail message.
After a message has been sent to the maximum number of recipients
allowed, Sendmail sends the error message 452 Too many recipients
to the sender of the message.
This will work only when all the recipients of the mail message have
their mailboxes on the same machine.
Timeout.*
• You can set the total time spent in satisfying a socket control request
using the Timeout.control option. The default setting for this
option is:
#O Timeout.control=2m
• You can set the resolver’s transmission time interval (in seconds)
using the Timeout.resolver.retrans option. This option sets the
Timeout.resolver.retrans.first, which sets the resolver’s
transmission time interval (in seconds) for the first attempt to
deliver a message. It also sets the
Timeout.resolver.retrans.normal option. The default setting for
this option is:
#O Timeout.resolver.retrans=5s
#O Timeout.resolver.retrans.first=5s
#O Timeout.resolver.retrans.normal=5s