よろしくおつたえください

It seems you can say
よろしくおつたえください
or
よろしくつたえてください
but not
よろしくおつたえてください.

How does this work?
The second one is a standard xxxte-kudasai construction.
But it seems you cant add the o-prefix (which usually goes with nouns?), you drop the te ending.
And in the first one, what is the grammatical basis, without the te?

"O + the -masu stem of a verb + kudasai" is an honorific expression of "~te kudasai".