Welcome to the Community Forums! Thanks for your post.
I'm sorry to hear you're having some trouble sending emails to your Virgin Media email account from your work email.
Do you have another Virgin Media mailbox/email account which you can try sending the same email to (with the same content included), so we can see whether the error is a result of the Virgin Media email servers not liking the emails?
I just wanted to check. In case it could help your fellow community members in the future. Remember if you ever need assistance in the future, our fantastic community and forum team are always willing to lend a hand.