The "Can I send you an email" is an entirely different story. Your ability to actually deliver the email is, however, is still a bit of permission. Not so much the asking The Amazing You permission...the "May I?" because there's really no one to ask permission of...but the finding out through testing whether you can actually get the email to move all the way from your "out basket" to your intended recipient's "in basket."
This is the more technical side of email marketing, and it can be much trickier. The "can" for email marketing consists of whether your prospective subscriber has the right kind of software to receive your email in the format you've designed it...and...(the part about finding out if you got permission without saying "Mother may I?") is whether you can (have the ability to) get your content and layout to pass through the permission police of the numerous spam filters currently used by Internet Service Providers (ISP's) as well as any additional filters added by your prospective subscriber.