Work through this after every migration. Problems found now are cheap; problems found in three weeks are not.
IMMEDIATELY
The homepage and several inner pages load correctly Images display, including in older content Contact forms submit and the notification arrives Login to the admin area works Search, filters and any interactive feature behave The checkout completes, if you run a shop
HTTPS
AutoSSL has issued for every domain and subdomain The padlock shows with no mixed-content warning HTTP redirects to HTTPS
Send a test message out, and receive one in, for every mailbox Devices and mail clients are reconfigured to the new server SPF and DKIM are correct under cPanel > Email Deliverability
BEHIND THE SCENES
Cron jobs recreated and running. On our servers, WordPress needs a real cron job because HTTP wp-cron is blocked. Permalinks re-saved so rewrite rules regenerate
File permissions correct: 755 folders, 644 files
Backups configured and running
FINALLY
Check Google Search Console for crawl errors after a few days, and keep the old hosting for a week before cancelling.
