Hi ​@Barb J! Can you describe the error message you’re getting? Are emails appearing to be sent and then bouncing back, or something else? That will help determine what’s going on here. 
Based on your answer, we can try to troubleshoot this. If the emails appear to be sent in Aspire but don't go out/customers don’t receive them, I always recommend checking your email sync as a first step. This knowledge base article describes that process.

Hi This is the error below, I have just adjusted my Synch settings, thank you . Will see if that works.

​@Barb J, we most commonly see this error for sync-related issues, and updating those settings should correct it. Let me know if you’re still seeing errors, but fingers crossed that fixed things! 

Thank you so much , so far no rejected emails today .