I rode somewhere that one can always put an "o" between the different elements that form a word in an agglutinated word.
According to this logic retpoŝtadreso and retpoŝtoadreso both should be fine. Am I wrong?
Anyway I reported it.
Yes, you're wrong.
The 'o' is only added to break up clusters of consonants, since many Esperanto speakers come from languages where those clusters are uncommon or forbidden. Since there's already a vowel at the junction point, you don't need the 'o'.
Hmm… I've never seen that before. By the way, I think you meant "read". :)
I put simply "retadreso" and it was accepted, but I wonder if that means more simply "intetnet address"; what we'd likely call a URL technically. How is it used in practice?
According to Wiktionary, "retadreso" is a URL and "retpoŝtadreso" is an email address.