Yes an email is too far.
I'm sure they are used to not getting an answer straight away, that's why we have voicemail.
As long as you are polite and apologise over the phone on return call. Remember they are paid to place you, you calling them back is a favour to them.
Would an apology email be too much?
That's a difficult question to answer since none of us are this person trying to call you.
That said, it's somewhat typical for recruiters to have to play a bit of "phone tag" with candidates, especially since recruiters are typically calling candidates during normal working hours, and many candidates are working current ...