Hi Lee and David,
Thank you for pointing this out to us. You are correct on all counts here. This is something we've seen start to pop up and it seems to mostly impact newer Android 6.x devices, in the GMail app with an Exchange (ActiveSync) account. This looks like it is due to the reply token string being a long, unbroken text string in fact. This is causing the newer device mail clients to scale text incorrectly.
We have a fix in testing right now which should constrain the token string to a 300 pixel container and force it to wrap properly. That way the email clients will not interpret it as a long, unbreaking string and try to scale the email text strangely. This fix will go out this weekend so you should see the difference Saturday.
If there is anything else we can do to help, please let us know.