Manage Simple Mail Transfer Protocol server performance

These are tips for managing a busy Simple Mail Transfer Protocol (SMTP) server that uses multiprocessing.

Your SMTP server might be busy because it uses all its capacity for adding and ending prestart jobs for each e-mail request.

If you find that the number of prestart jobs is affecting iSeries™ performance, you can set the threshold lower. If you want more jobs, you can set the number of prestart jobs higher.

With prestart jobs, every e-mail request runs as its own job. This method allows each job to focus solely on its client or server program's needs and requests. Each job can make longer time-out calls to enable the posting of host names for the purpose of not receiving unsolicited bulk e-mail.

To manage a busy SMTP server, you can change the following values:

• The number of jobs to start on initialization
• A threshold number for jobs
• The number of jobs to add when the server reaches the threshold
• A maximum for the number of running jobs to allow
• Selecting a subsystem for jobs

To manage a busy server, you need to change values on the SMTP server and the SMTP client.

The SMTP server works with the daemon and prestart jobs: QTSMTPSRVD and QTMSMTPSRVP. The SMTP client works with the daemon and prestart jobs: QTSMTPCLTD and QTSMTPCLTP.

To change the values on the SMTP server, follow these steps:

1. In the iSeries character-based interface, type CHGPJE (the Change Job Entries command). The Change Job Entries display appears.
2. Enter the following values at the prompt and press Enter:

These values guarantee that the server will start four prestart jobs, start two additional jobs when the available jobs fall below two, and allow a maximum of twenty prestart jobs.

• Change values for the Simple Mail Transfer Protocol server
  
• Change values for the Simple Mail Transfer Protocol client
  
• Select new subsystem for Simple Mail Transfer Protocol server jobs