Mail delivery failed: returning message to sender

hello, i can not solve the problem, and my site must be operational in 2 days. Help me please…
When I test the sending of the mail from the form “Email Inquiry”, I receive in undesirable message “Mail delivery failed: returning message to sender”. I specify that the sending of mails from my other forms works very well. I tested using other email addresses, always the same problem that resists.
I only have the problem with Email Inquiry.
What should I do?
Thank you for your help.

• This topic was modified 6 years, 2 months ago by edesign36.
• This topic was modified 6 years, 2 months ago by edesign36.

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