Pick the phone and call the Venue directly to seal the deal or at least to advise the E-Mail with Soundlinks & Band-Information you will send within next 30 minutes.

If you send an Email, think about the following:

Whenever the responsible person is available, address your E-Mail personally.

Do not overwhelm the recipient with too much data/information, limit yourself to the essentials.

Short Bio including your Sound-Style (Rockband, Metalband ...)
Press-Kit (one pdf not more than 5MB - if too large, try to convert with a pdf-program; right click on the pdf...)
Live-Gig-Links - only good quality (2-4 Links)
Follower Count Facebook/Instagram (only if the number is high enough)
Your motivation ("sell" yourself)

if you don't receive a reply from the venue, call them directly
(after 3-4 days; at latest after a week)