In a previous post I mentioned that I couldn't subscribe to the del.icio.us mailing list. No I wanted to post to the WSG mailinglist, but this was also in vain. So I started to play a little bit around and noticed, that if I send the mail through gmail itself, there is no problem subscribing to the del.icio.us list :-? So there must be somewhere a domain check comparing the actually sender domain with the domain part of the sender e-mail address.
While I completely understand that this check is necessary to prevent spoofing/phishing it's still at least for me very annoying since I can't really afford a real mailserver to send my mails... although, actually sending shouldn't be a big problem since I normally don't send too many large mails per month. Still, it's really annoying for me since it used to work quite fine before :-(