Forum Discussion

Nimbostratus

Apr 06, 2015

iRule to modify SMTP mail content

Hi, We have an requirement, where in we need to inspect the incoming SMTP message, look for a particular string and based on that modify the mail content. I have written the below iRule but this is n...

Nimbostratus

May 07, 2015

Hi, Thanks for your help :) I tried the code shared by you. It works fine when i test it using TELNET. But when i send an email from the Exchange server, the connection resets in the DATA section and the mail is not delivered to the back end server. The moment i remove the iRule for F5, all emails in the queue start flowing to the backend server. Please find below the logs printed during one such transaction. Thanks

May 7 13:59:39 LABPMCUSEXTLB01 info tmm[14744]: Rule /Common/LAB_SMTP_Enrichment_v2 : Old payload: EHLO AUT22EH000LABWI.domain.com May 7 13:59:39 LABPMCUSEXTLB01 info tmm[14744]: Rule /Common/LAB_SMTP_Enrichment_v2 : Old payload: MAIL FROM: May 7 13:59:39 LABPMCUSEXTLB01 info tmm[14744]: Rule /Common/LAB_SMTP_Enrichment_v2 : Old payload: RCPT TO: May 7 13:59:39 LABPMCUSEXTLB01 info tmm[14744]: Rule /Common/LAB_SMTP_Enrichment_v2 : Old payload: DATA May 7 13:59:39 LABPMCUSEXTLB01 info tmm[14744]: Rule /Common/LAB_SMTP_Enrichment_v2 : Old payload: DATA RSET

nitass
Employee
May 07, 2015
is it complete log? i think i do not see "New payload" in the log.
Ajay_Koushik_19
Nimbostratus
May 07, 2015
Hi, Yes this is the complete log. The "New Payload" is not called because the message does not reach that part of the code. The moment, DATA section starts, we see a RSET and the mail hangs in F5 and is not delivered to the backend server. This only occurs when the message is received from the Exchange server. Works perfectly fine when i tested this from TELNET.
nitass
Employee
May 07, 2015
can you try tcpdump? tcpdump -nni 0.0:nnn -s0 -w /var/tmp/output.pcap host x.x.x.x or host y.y.y.y and port 25 -v x.x.x.x is virtual server ip y.y.y.y is pool member ip