I have my own domains that I use for emails and I like to create a separate email alias for each company I deal with, so that if someone starts spamming me I know who it is and can block them. There is no mailbox storage behind these, they just redirect to real mailboxes at my ISP or GMail.
I've been using mydomain.com for this and it works well, except for one thing: it takes several hours for any changes to take effect. So If I want to register on some website I need to log into mydomain.com, create the new alias, wait 3-4 hours and then go back and register. This is obviously not ideal - I'd like something more immediate. There should be no limit on the number of aliases, though and it should be quite easy to create them.
Can anyone recommend an alternative service?