Problems with braefing via e-mail
Moderators: andreas.kippnick, Stefke
Problems with braefing via e-mail
Hi everyone,
I was given breafing for SBC_day1 today in 14:00 UTC. Nice but i think, that is late for me, because start of this task was yesterday at 18:45 UTC. I had the same problem with test2. Test1 was delivered to my e-mail 30 min. before start. Am I alone?
I was given breafing for SBC_day1 today in 14:00 UTC. Nice but i think, that is late for me, because start of this task was yesterday at 18:45 UTC. I had the same problem with test2. Test1 was delivered to my e-mail 30 min. before start. Am I alone?
- andreas.kippnick
- Posts: 719
- Joined: Tue Feb 07, 2006 10:10 pm
- Location: Stuttgart, Germany
- Contact:
On race days we sent the emails one hour before your time zone starts. That means a script is called every minute and when the time to send is reached we send about 150 email, one minute later 150 emails, one minute later 150... until all mails are sent to our mailserver.
I think the following scenery happens:
We sent the email at 17:45 UTC your InternetServiceProvider reject the mail the first time and accept it a few hours later (greylisting). That greylisting is a kind of spam protection. A mailserver reject a mail the first time with an error code 4XX not avaiable at the moment or something like that. The ISPs' mailserver logs which mailserver has submitted the mail and blocks all further mails from this mailserver for a certein time (minutes/hours/days). A "real" mailserver tries to submit the email again and again a few minutes/hours later. At the second/third/xxx time the mail is accepted by the ISPs' mailserver.
Just use the CCC to get the taskinfo
Andreas
I think the following scenery happens:
We sent the email at 17:45 UTC your InternetServiceProvider reject the mail the first time and accept it a few hours later (greylisting). That greylisting is a kind of spam protection. A mailserver reject a mail the first time with an error code 4XX not avaiable at the moment or something like that. The ISPs' mailserver logs which mailserver has submitted the mail and blocks all further mails from this mailserver for a certein time (minutes/hours/days). A "real" mailserver tries to submit the email again and again a few minutes/hours later. At the second/third/xxx time the mail is accepted by the ISPs' mailserver.
Just use the CCC to get the taskinfo
Andreas
Greylisting can be set up many different ways, but most correctly configured MTAs that use greylisting will only reject the very first attempt from a legitimate sender to send an email to a valid recipient. They will not put an arbitrary delay on the second attempt. All subsequent attempts will be allowed through first time (for the same sender IP, email envelope address and recipient).kippnick wrote:...The ISPs' mailserver logs which mailserver has submitted the mail and blocks all further mails from this mailserver for a certein time (minutes/hours/days). ...
A legitimate mail server will retry just a few minutes later (15m used to be the queue retry default). The receiving MX will then usually accept the mail. Retry intervals on a 450 error are configurable by the mail system admin. But the first retry is usually after just a few minutes.
This is based on the fact that most spam bots never retry. When they get the 450 error from the receiving MX they do nothing and skip to the next address on the recipient list.
Mark
Reg-#: G-1956
Comp-#: MT
Comp-#: MT