In my personal opinion any message in the form of "you were missed etcetc" is quite annoying, regardless of who is sending it.
Anyone can decide for their own whether he/she wants to visit a website again or not. One should not "push" people towards something.
I own a SMF forum myself and never send messages to my members.
I can quite understand the caution taken by the topic starter rhomp2002 .
Any email containing weblinks should always be treated with caution all of us know.
In my opinion the proper way of forum (member) managment is to either delete every once in a while all members that have not logged in again for a period of x days OR -a bit more elagant- send a warning that the account is expiring and that members should log in again within a week to avoid deletion of their account (no URLs needed, just a message upon which someone can act or that someone can neglect).
We forbid and the statement, which stinks the email to the sky and you try here the forum to make bad.
BTW: Please Andreas could you stop reacting so agressively/impulsively/obviously offended ( I am referring to your bold marked text
) (also your english gets worse / less understandable once your emotions take the lead
), the topic starter is honest and integer and was just cautious, I do not get the impression at all that he was attacking one of the mentioned webforums or blackmailing thiem or wanted to offend you, he was just unsure. He was really unaware of the name of the administrator, and unknwon makes cautious, that's a natural reaction and should be regarded as such.