These days there's also to consider that some Mail Threat Protection Tools (at least Microsoft Defender in Exchange Online does this) click links in Mails to check them.
Recently ran into this issue as new mail accounts got confirmed automatically and magic links were invalid when the user clicked them, because Microsoft already logged in with it during checking.
Recently ran into this issue as new mail accounts got confirmed automatically and magic links were invalid when the user clicked them, because Microsoft already logged in with it during checking.