On Tue, Apr 12, 2011 at 12:12 AM, Nathanael C. Cariaga <nccariaga@stluke.com.ph> wrote:
Strangely though I noticed that the email accounts that seems to be affected by our concern seems to be related to the Yahoo SG servers.....
Oh. You don't seem to want to accept connections from the singapore servers at all: -bash-3.2$ telnet qc.stluke.com.ph 25 Trying 219.90.94.56... Connected to qc.stluke.com.ph. Escape character is '^]'. 550 Blacklisted: Blocked - see http://www.spamcop.net/bl.shtml?115.178.12.223 Connection closed by foreign host. -bash-3.2$ So, they really can't send mail to your users--but it's your machine rejecting the connection. :/ Matt
On 4/12/2011 3:04 PM, Christopher Balmain wrote:
We had a lot of issues delivering mail to yahoo.com.sg about a year ago (just the .sg domain, plain .com was fine). Could establish connection but it'd die halfway through transferring mail. A static route to drop the MTU (for their subnet only) to 1000 fixed the problem right up.
Not sure if pmtud was/is broken or what.
- Chris
On Tue, 2011-04-12 at 15:29 +1000, Nathanael C. Cariaga wrote:
Thanks anyway. I just find this issue intriguing since not all Yahoo mail accounts are affected. In addition, incoming mails from other domain doesn't seem to be affected. That is why I want to check if it is a network issue :)
-nathan
On 4/12/2011 1:17 PM, Matthew Petach wrote:
On Mon, Apr 11, 2011 at 9:54 PM, Brielle Bruns<bruns@2mbit.com> wrote:
On 4/11/11 10:47 PM, Matthew Petach wrote:
mpetach@opstools1:~> telnet 219.90.94.56 25 Trying 219.90.94.56... Connected to static-host-219-90-94-56.tri.ph. Escape character is '^]'. ehlo yahoo.com 554 SMTP synchronization error Connection closed by foreign host. mpetach@opstools1:~>
I imagine when port 25 stops giving 5xx failure message back, mail reception might improve. ^_^;
Works fine for me, your getting an error because your trying to send a command before receiving the first 220, aka RFC violation. As long as you connect, wait a moment without trying to send a command, your fine.
Doh!
See, that's what happens when you ask networking people to try to troubleshoot mail issues. ^_^;;
Sorry about that. :(
Matt
-- Nathanael C. Cariaga Network & Security Administrator St Luke's Medical Center
Tel (QC) : +63 2 723 0101 ext 5520 / 4206 Tel (GC) : +63 2 789 7700 ext 6035 / 6036 Tel : +63 2 356 5686 Mobile : +63 922 8735686 EMail : nccariaga@stluke.com.ph