Hi @Andrew Lopez ，
According to the error message you gave me, your email was rejected by Gmail because:
- Your sender domain name has an SPF record with a hard fail policy (-all).
- Your IP address is not authorized by your domain name's SPF record.
To solve this problem, you can try the following methods:
- Check if your SPF record is correctly configured, and if it contains the IP address or domain name of your mail server or third-party mail service .
- If your SPF record is correctly configured, you may need to contact your mail server or third-party mail service provider, and ask them if they have changed their IP address or domain name, or if there are any other problems that cause SPF check failure.
- If you do not want to use the hard fail policy, you can modify your SPF record, and use the soft fail policy (~all) or neutral policy (?all) . In this way, even if SPF check fails, your email will not be directly rejected or deleted, but will be marked as possible spam or phishing, and then processed according to the configuration of the recipient’s mail server .
Hope above can help you!
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