Reply-To: isn’t working since this morning

We have been working with Contact 7 for long time now, we receive all the emails from our website in our Gmail account. Today, when we tried to reply to our customers it’s showing our own email where they coming from, the header is correct, we didn’t change anything but still not replying to our customers as usual.

[your-name] <[your-email]>

Any thoughts about this issue guys? I will appreciate your support. Thank you.