i'm wondering if this will merge with html emal handler plugin:
or is this plugin just for plain text format?
It was designed to extend the plaintext e-mails sent by Elgg. You could probably change the subject/sender name using this, but header/footer content would probably end up outside the BODY of an HTML e-mail message (possibly breaking it).
If this were your only plugin, HTML in the header/footer would just show as raw markup.
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