There’s a big difference between writing appeal letters and writing grant applications.
When you’re writing a grant application you know that it will be read. In fact, someone is paid to read it.
When you’re writing an appeal letter (or an e-appeal) you know that it will arrive in a mailbox in competition with everything else the donor is receiving. No one is paid to read it.
That’s a big difference.
The audiences for grant applications and appeals are completely different. This explains why the writing style for an appeal is different than the writing style for a grant application.
If your grant applications and your appeals sound the same, one of them is completely missing the mark.