I know autoresponders like Aweber and Mailchimp hate when people try to upload scraped/non-double opt-in's to their mailing list. And as far as I can tell, people get banned for this.
What I am wondering is, how do you (and is it easy) to upload offline clients to your Aweber mailing list. These are offline clients that have asked to be put onto your list.
Keep in mind I currently have zero experience using aweber, so that's why this may come off as dumb, but does Aweber have a way to differentiate between 'offline email opt-ins' and purely stolen/non-canspam compliant mailing lists?