intermittent failures with sendmail

[Chuck Swiger]

Hi--

On Jul 2, 2009, at 8:33 AM, Alex Teslik wrote:
> Jul  2 03:35:16 gouda sm-mta[40342]: n5ULKB0i064252: SYSERR(root):  
> timeout writing message to
> b.mx.mail.yahoo.com.: Broken pipe
> Jul  2 04:23:01 gouda sm-mta[47860]: n5ULKB0i064252: SYSERR(root):  
> timeout writing message to
> e.mx.mail.yahoo.com.: Broken pipe
> Jul  2 07:03:05 gouda sm-mta[53788]: n5ULKB0i064252: SYSERR(root):  
> timeout writing message to
> d.mx.mail.yahoo.com.: Broken pipe
>
> I thought it might be an MTU problem:
>
> http://anthony.zerosandones.co.uk/?q=node/451
>
> I set my MTU to 1300, but that hasn't helped.
>
> [gouda:root]/home/alex/acatysmoof.com/services# ifconfig -a
> em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu  
> 1300
> 	options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4>
> 	ether 00:1c:c0:36:85:62
> 	inet 24.205.141.134 netmask 0xfffffffc broadcast 24.205.141.135
> 	media: Ethernet autoselect (100baseTX <full-duplex>)
> 	status: active
>
> DNS is working fine everywhere, so I don't think thats it. PTR is  
> fine, reverse lookups work fine.
>
> I've googled my brains out. Does anyone have any ideas?

Intermittent network connectivity problems could be a firewall problem  
or an actual physical connectivity issue.  Presumably your ISP can run  
a line quality test or something for your DSL/cable/T1/whatever link.   
tcpdump might give some insight, also....

Regards,
-- 
-Chuck