For some time now we have been rolling out an efficient method of spam protection for our clients called Greylisting.
The way greylisting works like this:-
1. A user sends email
2. The users email account tries to deliver email to your mailbox
3. Your mailbox rejects the email once
4. The users email account tries again to deliver email (this is normal practice)
5. Your mailbox accepts the email and makes a note to allow any future email from this email address
The efficacy of greylisting lies in the fact that many spammers do not use a normal ‘Mail Transport Agent’ and therefore, rejected email will not be queued for a second attempt at email delivery
Quite simply, the largest advantage is a reduction in spam email which saves you time and reduces the load on the server.
IMPORTANT: There are 2 potential scenarios where issues may occur when using greylisting:-
1. A genuine email server is not set up correctly and also doesn’t attempt re-deliver (should be quite rare)
2. Online services with a ‘forgotten email address’ or ‘signup’ sequence (such as on online shop) may not attempt a second delivery.
Both of these issues can be circumvented by letting your system administrator (in the case of Adira clients, this is me!) know what email addresses are unable to deliver email. I will then add them to a whitelist for you.
You also need to be aware that, because of the way greylisting works, you may experience some delay in receiving email while the server rejects it and waits for it to be redelivered. This should only happen once since the email address relating to accepted mail is stored and remembered.
I am, of course happy to answer any questions relating to this, or any matter of hosting or website design. Feel free to call me (Phill) on 0845 6121199.