bounced emails

Hi Homestead Team, I am having the same problem as many others. This is the second time I send this email.

I hope it can be solved asap. It is not good for business and very time consuming. This issue has been

happening for months now. :(

My emails are bouncing back for different reasons.  These are the two messages I receive. 

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

    host hotmail-com.olc.protection.outlook.com [104.47.11.97]
    SMTP error from remote mail server after pipelined sending data block:
    550 5.7.1 Unfortunately, messages from [66.96.186.9] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [DB5EUR02FT041.eop-EUR02.prod.protection.outlook.com 2023-05-10T20:11:06.904Z 08DB5165622BA6C2]

SMTP error from remote mail server after end of data:
    550-5.7.26 This mail is unauthenticated, which poses a security risk to the
    550-5.7.26 sender and Gmail users, and has been blocked. The sender must
    550-5.7.26 authenticate with at least one of SPF or DKIM. For this message,
    550-5.7.26 DKIM checks did not pass and SPF check for [bckelp.com] did not pass