From 1st Feb Google and Yahoo will be enforcing certain standards, and emails that do not comply will be rejected.
In order to send emails to either service you will need :
– a valid SPF record
– a valid DKIM record
– a valid DMARC record with the policy set to at least “p=none”
Any email which does not contain a valid SPF, DKIM and DMARC record will be rejected with a bounce back similar to “421 4.4.2 Connection dropped due to SocketError”.
We have created a guide on what these records are and how to check if you are compliant: https://www.globe2.net/blog/spf-dkim-dmarc/
If you are still unsure if you are compliant or what to do, we may be able to help, get in touch.