Got a question for ya

I've been thinking about email and texting etiquette.  I need your opinion.

When you text someone, when do you expect a reply?  Or do you even expect one?
Yes, I realize it depends on who you texted.

If I text my husband - I expect a text back QUICK
If I text my child - I expect a text back IMMEDIATELY  (unless they are driving but I pretty much know where they are and what they are doing by looking at the clock so.....)

The Engineer and I had this discussion.  Many, many times he does not reply to my texts.  I told him I really need him to reply.  Even if it's just "okay"  You know?

When I text my hairdresser for an appointment I expect a reply within a day.  Or two.

When I text a friend, I expect a reply within a day or two.  But honestly?  I'd like a quicker reply.  Especially because the friends I text absolutely have their cell phone with them ALL THE TIME.

I have one friend who never replies to texts.  N.E.V.E.R.  Why do I text her?  That is a very good question.  I don't anymore.

My other question is part two of the first question.  What do you expect from email?  I don't really mean work email.  I work at a paperless school and we email often, answer questions by email, communicate online, etc.  I've never had a problem or a delay in having a question answered, etc. at work.

But in my "real" life, I have a big problem.  Let's just say this: I emailed an old friend upon learning that her son graduated from high school last week.  No reply.

I emailed a friend who now works at another school at her school email addy.  No reply.

I'm beginning to get a complex!

When I receive an email, I reply within a day.  I'm an early riser.  Every morning I get up super early while everyone else is sleeping, grab a cup of something warm, sit in front of the computer and read.  I read emails, I read blogs, I check the weather, etc.

What is the rule of thumb when it comes to electronic communication?