Change mail format and delete list

[alomari]

Hi,
I have imported a list of emails from csv file, but when i checked the mail format, i found out that it is "TEXT". how can i change it to HTML to all recipients at a glance and how can i delete a list of recipients
Thanks

[elena]

Hello,
Please! I have the same question! how can I change mail format in many recipients at once?
thanks,
Elena.