If email stopped working immediately after a DNS change, check the domain's MX records first. Don't start changing multiple DNS records until you know which service is supposed to handle your email.
DNS changes can affect more than your website.
When a business changes a domain, moves hosting or updates DNS, email can sometimes stop working even though the website still looks completely normal.
1. First: don't change everything at once
Before changing DNS records, identify exactly what stopped working. Can you send email? Can you receive email? Is the website working? Was anything changed immediately before the problem appeared?
2. Check the MX records
MX records tell the internet which mail service should receive email for your domain. If they were removed, changed or pointed at the wrong provider, incoming mail can stop working.
3. Check SPF, DKIM and DMARC
These records help mail providers authenticate messages and protect your domain. Confirm which provider is actually sending your mail before changing them.