Problem with sendmail 8.13.7

[Stefan Kuhlemann]

Hi  mailinglist

I have a strange problem with sendmail 8.13.7. (Fedora Core 5)

Sendmail is not able to send out any mail's. But: other smtp-hosts are 
able to contact and deliver mails to this sendmail. The acutal 
configuration did work until the last update via yum (which included the 
sendmail update).

More mysterios is: Using telnet from this host, I am able to send out 
mail's without problems....

The sendmail log files says: (loglevel 15)
Jul 23 19:06:38 sleeperbase sendmail[21362]: k6MKtL56014195: 
makeconnection (somehost.com. [1.2.3.4]) failed: Connection timed out 
with somehost.com.

Some sniffing gave the following result:

The SMTP-connecion opens, the remote host send it's greeting but the 
local sendmail does not send an EHLO or HELO ... it doen't do anything 
and the connection times out.

Sniffing at the remote host:
The connection establishes successfull, the host sends it's greeting, 
but then there will be no answers from (this time the remote) sendmail, 
after some retransmits the connections times out.

Any ideas?

Stefan