The use of the word “would” is out of context. Your sentence inclusion of “send the the…” one “the” needs to be removed. Also, mentioning dates of arrival is somewhat redundant because the date of arrival itself is one of or a part of the flight details. “Later” is extremely vague and informal when talking to “His/Her Excellency”—later could mean in 2 seconds, minutes, days, weeks, months, years, decades; you’d be better of stating specifically when you’ll provide the information or if that’s not possible because it’s dependent on something that is beyond your control, you state at the conclusion of the “something” that has to occur first. I’ve provided an example below.

We will provide the flight details once the [travel]arrangements have been confirmed.

We will send the flight details and dates of arrival at a later date*. Should there be any need to add members to the delegation, we will immediately inform Your Excellency of the changes. Thank you very much for Your Excellency’s kind assistance.

*We might send the info and details of your flight on the big ol’ airplane and the date that you will get to whatever place your gonna go some other time, we’re just not sure when.*

The flight details, and arrival dates, will be sent later.

It would be beneficial to relay information regarding the flight at a later date.

or

We believe it would be beneficial to information regarding the flight at a later date.

“We will send the flight itinerary at a later date.”

That’s teh best I have.

The word “would” implies that there is some possibility that you might not. Therefore I suggest “shall.”

Details of flight and arrival shall be forthcoming.

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Y’all just keep an eye on that ‘ol mailbox of yours and it should be showin’ up ’bout any time now.

Best Wishes

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