Word Choice

It's a bit awkward and wordy.

I left a message asking the plans examiner to discuss the code upgrades with Mike.

OR

I have asked the plans examiner to meet with Mike about ...

Just ask yourself what's crucial in the message. The time of day is or isn't. Emailing, voice-messaging is or isn't. Meeting or talking one the phone - is or isn't. Re: Meet and discuss - they don't have to meet in order to discuss, also what else are they going to do when they meet BUT discuss? They aren't going to sit there and play cards.

Great, thank you!

I messaged the plans examiner to schedule a meeting to discuss code upgrades with Mike and myself.

What (I messaged) Who (the plans examiner) Why (to discuss code upgrades)
Pertinent detail - (with Mike and Myself) - if important information for the person I am informing about who, what, why with an indefinite when and where until I get a response.