Is it grammatically correct to use よう without な, に or だ（です）after it?

Question

神の思し召しであなたとよき友情を育むためにあなたにメールするようお告げがありました

I think the sentence roughly translates into: "For the sake of raising you and good friend into God's thoughts, you mailed a divine message"

Instincts tell me that there should be a な or に before/after the よう in the sentence

I found some pages on the net discussing the proper usage of よう in a sentence from this site and here. All of the examples had ような、ように、なよう, and によう.

I did come across a sample that was written as 話せるよう. The thing that has left me confused is that nothing came after よう.

Was I right to suspect this sentence as being grammatically incorrect or am I completely off the mark?

Answer 1

YES, That is right.

"メールするよう(に)お告げがありました"

"に" is optional.
Here, "ように" or "よう" is used in the sense of such instructions or request.

or

"メールするよう(に との)お告げがありました"
"メールするよう(に という)お告げがありました"

as other example

"上司から今すぐ帰社するよう(に)連絡がありました"
"医者に規則正しい生活を送るよう(に)言われました"