We recommend email, as this is now by far the most common form. If in doubt with other words, hyphenate – this is the most comprehensible form of such words.
That same section also has a page on how “ye” came about, and why it doesn’t mean “the”:
The use of ye for the, like the use of f for s, results from a misreading of old letter-forms, in this case the letter ‘thorn’ (for the sound ‘th’), which in its plain version looks like a p with the stem extended above the loop. ‘Thorn’ originated as a runic letter, and is still used in writing the Icelandic language.
Apparently it was mainly used to refer to more than one person as the subject of a sentence.