Verify the mobile server settings again from the email provider. It might have changed since the last time you retrieved the information.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.
I have a J320V and ever since I got a new laptop, I cannot connect the Samsung to email. It says Security connection occurred. Why? I also cannot find where to get into the IMAP setting on this phone. I'm not tech savy and there is no Verizon store around me. Thanks.