Create a contact group

I need a contact group for our escalation list. Create a group named Escalation Team with these ten people: Maria Gonzalez (maria.g@gurovpartners.com), Jamal Reed (jamal.reed@northpoint.org), Priya Sharma (priya.sharma@brightline.co), Tom Hayes (t.hayes@acme-industries.com), Li Wei (li.wei@delta-tech.cn), Elena Popov (elena.popov@sinclair.eu), Ahmed Nassar (a.nassar@mediserv.io), Susan O'Brien (s.obrien@greenfield.uk), Carlos Mendez (c.mendez@almacorp.mx), and Nina Patel (nina.patel@orchidhealth.com). Make sure each address is added and the group is visible when composing mail.

Before I share this escalation group with the team, make it easy for others to use: list the members and highlight any with alternate addresses, show who is external to our domain, suggest a shorter display name for mobile, and flag any duplicates or formatting errors in the addresses.

I tried to add the tenth person to Escalation Team and the interface accepted the name but the address did not stick. I am worried I missed a typo or that person is blocked by a directory rule. I cannot see directory sync logs. What is the likely cause and the fastest way to confirm and fix it so the group is complete before our 4pm incident drill?

Over the last quarter I keep rebuilding near-identical contact groups for each incident type and losing time resolving mis-typed emails. Help me change my habit: what naming convention, verification step, and handoff checklist will stop duplicate groups, catch typo’d addresses, and let anyone on the rota reuse the right group quickly?