"Ae" in the english languae is usually pronounced as like a short vowel "A" as in Cat.
So Daemon would be pronounced Dammon.
International Phonetic Alphabet
The symbol [æ] is also used in the International Phonetic Alphabet to denote a near-open front unrounded vowel like in the word cat in many dialects of Modern English, which is the sound that was most likely represented by the Old English letter. In the IPA, it is always in lowercase.
https://en.wikipedia.org/wiki/%C3%86

It's not English, but I still use the old "when two vowels go walking the first does the talking"

I incorrectly pronounce it 'DAY-minn' (phonetically), since 'dae' technically sounds like 'day'. So if I sent an email to Matt Damon, SMTP would communicate with Matt Damon's daemon.

Day'-min
 

I say day'-min. I think I used to say dymon (die'-mon)

It's all Ggreek to me
 

Demon (Greek Δαιμων = a mischievous spirit)