IBM Support

Enable/Disable DNS Queries for MSF and SMTP to Allow Blind Forwarding All E-Mail Directly to External Mail Server

Troubleshooting


Problem

By default, both MSF (Mail Server Framework) and SMTP (Simple Mail Transfer Protocol) use a DNS query of the domain of the target e-mail to define further actions to be taken. The DNS queries are unncessary if all e-mail is to be forwarded to a remote mail server for handling. PTFs have been released that shut off the additonal processing and DNS queries by both MSF and SMTP.

Resolving The Problem

By default, both MSF (Mail Server Framework) and SMTP (Simple Mail Transfer Protocol) use a DNS query of the domain of the target e-mail to determine further actions to be taken. The DNS queries are unnecessary if all e-mail is simply being forwarded to a remote mail server for handling. The system allows the unnecessary processing and DNS queries by both MSF and SMTP to be shut off using the following steps:
*************************
* Enable this function  *
*************************

1) Stop SMTP and MSF service
 
ENDMSF

ENDTCPSVR *SMTP


2) Open the function and set the mail router and firewall

a. If enable this function first time, a system scope environment
variable should be created for switch:
 
ADDENVVAR ENVVAR(QIBM_SMTP_FWDSVR_LCL_MAIL) VALUE('YES') LEVEL(*SYS)

If the environment variable has been created, change its value
to *YES:
 
CHGENVVAR ENVVAR(QIBM_SMTP_FWDSVR_LCL_MAIL) VALUE('YES') LEVEL(*SYS)

b. Run CHGSMTPA to set "Forwarding mailhub server" if not already defined.

3) Start SMTP and MSF service:
 
STRMSF

STRTCPSVR *SMTP


Note- If the system is configured to receive email as an SMTP server this function will cause all email to not get delivered to users mail boxes but instead route the email directly to the router. Do not use this if you are receiving mail on the IBM i

*************************
In the event it is desired to reconfigure SMTP and start sending e-mails out directly (no longer using a remote mail server), it would be necessary to disable this function (which would turn back on DNS queries). This can be done using the following steps:

*************************
* Disable this function *
*************************

1) Stop SMTP and MSF service:
ENDMSF

ENDTCPSVR *SMTP


2) Run the following command to disable to functionality:
 
CHGENVVAR ENVVAR(QIBM_SMTP_FWDSVR_LCL_MAIL) VALUE('NO') LEVEL(*SYS)

As for "Forwarding mailhub server" configuration, it can be kept or disabled based on the requirement.

3) Start SMTP and MSF service:
 
STRMSF

STRTCPSVR *SMTP


 

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Historical Number

653461906

Document Information

Modified date:
23 August 2024

UID

nas8N1010638