When the i5/OS SMTP server is used as a primary e-mail server, performance problems can arise when a lot of spam e-mail is received. The SMTP server can be tied-up generating non-delivery notifications for each spam e-mail received.
To avoid this situation and increase performance, release V5R3 PTF, SI17335 provides a new function that enables verification of a recipient on inbound e-mail. Following a failed verification, the e-mail is rejected rather than creating a non-delivery notification.
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