You should unsubscribe that email address so they do not get sent another email. If you don't then next time you send an email they will complain again and again until your complaint rate gets too high and your email is blocked.

Regards
Sean Duffy
Emailcenter UK
www.emailcenteruk.com

In this particular case the ISP could argue it was not actually this person that signed up so you should include a message like:

"If you believe you have received this in error please click here"

For complaints registered against a newsletter most ISPs when you respond to the complaint would strongly advise you use a double opt-in sign-up process so only the email account owner can confirm the subscription.

In reality I would be surprised if your transactional emails generated enough complaints from AOL or Hotmail to cause any problems but you need to have a feedback loop set-up before they will put any effort onto resolving any delivery issue you have with them, even if it is not to do with user complaints.

Sean

On 12:46:50 30 January 2008 JoDalton wrote:

Thanks Sean.

In one particular case, the email that was marked as spam was the transactional "welcome and thanks for registering email".

There is currently no unsubscribe link in this email - should there be even though its a transactional email?

Jo