GMail IFTTT Time Trigger/Suppressor

Most carriers have free email to sms gateway (standard sms charges apply) meaning you can send an email, which the carrier will convert to sms and send to the phone number.

With this as the case, you can just create an email rule within gmail to forward an email based on your filter rule, and the forward to email would be based on the number/carrier.

Not sure how out of date This website is, so you might have to find a new format to do it, but it is still very possible and easy. I set my gmail to forward an email to me as an sms on ATT.

From the website above the format of the email would be:

T-Mobile: [10-digit phone number]@tmomail.net Example: 1234567890@tmomail.net

A quick google search for "forward email to sms" will yield plenty of results.

As a bit of a spoiler, we tested this last night. I have two email address (which I will call for the sake of example "test1@gmail.com" and "test2@gmail.com"), and then we did this:

To:      Rebecca <Recip@gmail.com>
From:    My Name <test1@gmail.com>
Subject: this is a test
Body:  blah blah whatever

and additionally

To:      Rebecca <Recip@gmail.com>
From:    My Name <test1@gmail.com>
Subject: this is a test
Body:  this should nest under the other

and voila, they nested. No work required. And then we did this:

To:      Rebecca <Recip@gmail.com>
From:    My Name <test2@gmail.com>
Subject: this is a test
Body:  does this nest with the others?

And it didn't nest!

So in other words, two emails from the same sender with the same subject will nest. Two emails from two different addresses with the same subject will not nest.