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fixup smtp blocks WinCE

activating the fixup smtp feature blocks sending mails from WinCE. Tests with a Win95 client and a Palm worked fine.

Examining the packets with a sniffer show the following for Win CE:

S: MAIL FROM:<>

R: 250

S: MAIL FROM:<email-address>

Here the PIX stops transfering the packets.

Clients from Win95 and Palm start with:

S: MAIL FROM:<email-address>

As in RFC-821, page 15/16 described a 'MAIL FROM:' with an empty argument is handled as an undeliverable message. As shown in the example 7 it should be:

S: MAIL FROM:<>

R: 250 ok

S: RCPT TO:<@HOSTX.ARPA:JOE@HOSTW.ARPA>

Is it correct to interpret this example to be the only way to be RFC-conform when beginning with 'MAIL FROM:<>'.

Does this mean the way in that the WinCE-client acts is not RFC-821 conform and is correctly filtered by the PIX?

Any statements would be appreciated.

Thanks,

Alexander

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Re: fixup smtp blocks WinCE

Fixup SMTP in the PIX does keep track of what state the email message is in (initial command mode, reply mode, data mode, etc), so if things aren't found in the right order it will block it.

Page 27 of RFC821 details the command syntax, and says the following:

------------------------------------------------------------------

The MAIL, SEND, SOML, or SAML commands begin a mail

transaction. Once started a mail transaction consists of

one of the transaction beginning commands, one or more RCPT

commands, and a DATA command, in that order. A mail

transaction may be aborted by the RSET command. There may

be zero or more transactions in a session.

------------------------------------------------------------------

So it states that you can have only one MAIL command per mail transaction, so if WinCE is indeed sending out two then it's violating the RFC.

1 REPLY
Cisco Employee

Re: fixup smtp blocks WinCE

Fixup SMTP in the PIX does keep track of what state the email message is in (initial command mode, reply mode, data mode, etc), so if things aren't found in the right order it will block it.

Page 27 of RFC821 details the command syntax, and says the following:

------------------------------------------------------------------

The MAIL, SEND, SOML, or SAML commands begin a mail

transaction. Once started a mail transaction consists of

one of the transaction beginning commands, one or more RCPT

commands, and a DATA command, in that order. A mail

transaction may be aborted by the RSET command. There may

be zero or more transactions in a session.

------------------------------------------------------------------

So it states that you can have only one MAIL command per mail transaction, so if WinCE is indeed sending out two then it's violating the RFC.

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