Hey, On 09/29/17 15:06, Markus Rosjat wrote:
my boss is getting on my nerves that greylisting is basically out of date because of things like outlook.com and mails ending up delayed for ever. So the next logical step would be to deploy a tool like rspamd or spamassasin to examin mail content. These tools need to be trained and if you have a small mailserver with less accounts this could take a while I imagine
i assume that your boss is not an engineer and also not very familiar with how emails work. Greylisting it clearly NOT out of date at all. Greylisting simply makes use of stuff that is defined in the SMTP RFC. Every email server is allowed to temporary deny the delivery of an email and ask the sending server for another try.
The problem in this case is clearly Microsoft who has no idea how email is supposed to work. You have two options here.
A: Simply don't care about Microsoft and just send customers to a website where you describe the problem and tell them to contact Microsoft in order to fix there stuff. This works very well, my Company hosts around 2,3 Million mailboxes and we use Greylisting and customers are okay with it.
B: You exclude the outlook.com outgoing servers from greylisting. Microsoft provides a list of IP addresses that they use for delivery:
https://mail.live.com/mail/ipspace.aspx
65.54.190.0/26 65.54.190.64/26 65.54.190.128/26 65.54.190.192/26 65.55.116.0/26 65.55.111.64/26 65.55.116.64/26 65.55.111.128/26 65.55.34.0/26 65.55.34.64/26 65.55.34.128/26 65.55.34.192/26 65.55.90.0/26 65.55.90.64/26 65.55.90.128/26 65.55.90.192/26 65.54.51.64/26 65.54.61.64/26 207.46.66.0/28 157.55.0.192/26 157.55.1.128/26 157.55.2.0/26 157.55.2.64/26
Greetings Leo
