Sure but I have a catch-all and I'm not receiving e-mails to twitter@mydomain, or facebook@mydomain. It's not impossible that spammers decided tumblr is particu

Sure but I have a catch-all and I'm not receiving e-mails to twitter@mydomain, or facebook@mydomain. It's not impossible that spammers decided tumblr is particularly likely because they offer a version of the service in your domain but still pretty unlucky for tumblr. I must remember to do this for new things I sign up to. It is a good idea.