Unable to send mail to Gmail accounts

Hi, like others here, I'm getting mail bouncing back when I send messages to gmail accounts.  I have read through the posts of a number of others who have had this problem, hoping to be able to figure out how to solve it, but it seems to be something that needs to happen from the Homestead/Roundcube side.  

Can you please help me fix this?  I need to be able to respond to my clients!

This is the message I get back:

This message was created automatically by mail delivery software.

 

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:

 

  corbettkruse@gmail.com

    host gmail-smtp-in.l.google.com [142.250.102.26]

    SMTP error from remote mail server after pipelined end of data:

    550-5.7.26 This message does not pass authentication checks (SPF and DKIM both

    550-5.7.26 do not pass). SPF check for [sheilagticen.com] does not pass with

    550-5.7.26 ip: [66.96.189.2].To best protect our users from spam, the message

    550-5.7.26 has been blocked. Please visit

    550-5.7.26  https://support.google.com/mail/answer/81126#authentication for more

    550 5.7.26 information. qa6-20020a170907868600b00921c71c0f59si619049ejc.1000 - gsmtp