If an email service or browser flags an event login link as suspicious, take the warning seriously. A warning alone does not establish whether the message is genuine or identify which domain is responsible.
Check the message safely
Do not bypass the warning or enter passwords or payment details through a link you do not trust.
Go directly to the event website using an address you already know, or contact the event organiser through a trusted channel to confirm the message.
If you need help, send the organiser or HeySummit support the event URL, email service/browser, exact warning and time it appeared. A redacted screenshot is useful.
Keep complete magic login links private: they can sign someone into an attendee account. Do not post them publicly or paste them into public link-checking tools. Hide login tokens and personal information in screenshots.
For event organisers
Check the exact sender and destination shown in the affected message. A custom domain does not by itself prove the warning is a domain problem, and a HeySummit address does not by itself prove a message is safe. Ask support to investigate the actual warning before telling attendees to ignore it or allow the domain. For general guidance, see Google’s advice on suspicious and phishing emails.