I am unable to message the customer

[SANWILOFFICIAL]

I am unable to message the customer

[NanaLetha]

Why do you need to?

[BagmakerSupply]

@SANWILOFFICIAL: In what way are you "unable to message the customer"? What error / advisory message are you getting?

[PlatypusDream]

Your messaging privileges may have been suspended for soliciting and spamming other users.

FYI your "Donation" / "Tips" listing is not allowed on Etsy. It can be used for SHILLING.

Also, your "40 Free Listings" listing is not allowed either.

ALL listings MUST be a tangible good for sale, NOT advertisements or begging for donations.

Read the Terms of Use:

https://www.etsy.com/legal/sellers/

[JMOldeVintage]

@SANWILOFFICIAL  - There are two main reasons for an inability to reply to a potential buyers message.
First, that your may have sent out promotional messages a marketing tactic that many consider spam & is illegal in some countries. So Etsy muted your shop & you will have to wait for your messaging ability to return.

Second there is the current swarm of scammers out there. They send message to shops requesting your email, or a message states that a sale can't be completed until you provide your bank information. These messages are just that Scams. 
Etsy will usually catch the offenders & erase the account. So when you go to reply you will see something along the lines of "user name not found".
For these scam messages be thankful Etsy caught them. Mark these messages as "spam" and be done with them. Remember that real messages from Etsy will be in the "from Etsy" box in your shop's messages. Never give your email address or banking information to anyone sending you a message. If Etsy truly did need this information a banner requesting updates would be attached to your shop manager. 

[ZehOriginalArt]

@SANWILOFFICIAL 

If a "customer" messaged you saying they need your email or cannot purchase something and when you tried to reply, you got an error stating that the customer does not exist, that is because it was not a customer, but a scammer and Etsy has deleted the scammer's account. There are many scams online these days both on Etsy and elsewhere.

Protect yourself from scammers. Never give a so-called customer your email address. Etsy does not need it, they have it already. Do not click links in messages (or in emails). If you get a message that says it is from Etsy Staff or something similar, check your messages in a browser (not the app), and look for the section  under Messages>Inbox that says FROM ETSY. Click that. If the message does not appear in 'From Etsy', it is not from Etsy, it is a scam. Anyone can send a message to your inbox, but only Etsy can send one to 'From Etsy'.