No success in sending to gmail accounts or receiving from gmail accounts

No success in sending to gmail accounts or receiving from gmail accounts

Hello

I am having this problem with a specific email address in the domain accts@andalusarabicchoir.com.
I can neither receive, nor send from/to gmail accounts. The emails are sent without an error but nothing is received.

It is inconveniencing me with some of the choir members as no correspondence is received by them.

How can this problem be resolved?