odyssey book 5, line 29

[richard ross]

‘Ἑρμεία, σὺ γὰρ αὖτε τά τ᾽ ἄλλα περ ἄγγελός ἐσσι,

An exact, then sensible translation, please.

Richard Ross

[Paul Derouda]

"For you, Hermes, for your part, are [our] messenger with regard to other things as well".

αὖτε="for your part", "on the other hand", "as far as you are concerned", I can't find an exact English equivalent, but something like that; the idea is, I think, that this little word makes explicit that Zeus addresses now Hermes and no longer Athena.

τά τ᾽ ἄλλα περ="with regard to other things as well". It's difficult (at least for me) to pinpoint the exact meaning of every word, I sort of read it as one block. περ is often concessive ("although") but I don't think it's the case here, I suppose you'd rather call this use intensive ("even").

[Paul Derouda]

Or in better English:
"Since you, Hermes, are always our messenger".

This leaves αὖτε out.

[mwh]

“Hermes” (vocative) actually stands outside the γαρ clause, which is parenthetical, explaining why it's Hermes he's addressing (i.e. in his capacity as message-boy).

“Hermes—for you’re the messenger in everything else (in turn) too—(tell Calypso to send him home.)”

It's a common use of γαρ, strictly speaking elliptical, explaining why he's said what he's just said, especially common with vocatives:
"Hermes—(it's you I'm talking to) for you're the one who carries my messages—, tell ..."

The next line, with its imperatival ειπειν, continues directly from Ερμεια.