On topic: Once the E-mail goes out..it's gone!
Actually... (if anyone's curious) in email blasts like this, the banner is a graphic file which is housed on a server somewhere and referenced in the HTML, and downloaded to the email client only when you open it (and in some clients, when you click the "download pictures" link)... So yeah - if you make a typo in the actual TEXT of an email blast (like text that you could highlight with your cursor), its too late - everyone will see the goof. If its a typo within a static graphic, like the banner, you can change it, and re-upload your image to that server, and then anyone who opens it from that point on won't see your goof
I'm an ecommerce site mgr / designer guy, and I send out email blasts to about 20k people twice a month... have been known to have to re-upload an image or two in my time for dumb goofs I didn't notice. heheh
(although misspelling "and" with "anc" is MUCH lower impact than misplacing a decimal point or leaving off a digit in the price of a cluster of servers for sale - ack!!!!

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