If you need just one email (e.g.,
abc@domain.com) spelled out you can put it as
a, b, c, at, d, o, m, a, i, n, dot com
You can also create the following entry in Pronunciation editor
Word:
abc@domain.com
Pronunciation: a, b, c, at, d, o, m, a, i, n, dot com
so that every time "abc@domain.com" occurs in text, it would automatically get spelled out as if it was written as "a, b, c, at, d, o, m, a, i, n, dot com".
Some voices may require changing the letter "a" to something like "aey" in order to be pronounced correctly
aey, b, c, at, d, o, m, aey, i, n, dot com