I sent email from Mass Mailings 250 email but it successfully sent just only 50 email
3 days ago, It's still show 200 emails could not be sent.
I tried to click "Retry" many times, It's still show 200 emails could not be sent.
I test to send a new mail list around 10 email, all email can be sent successfully.
Why it cannot send the remaining 200 emails when I click retry?
How to fix it?
Anyone please advise.