#email 4 articles

• E-mail HTML built like a web page falls apart in Outlookgotchas / graphClassic Outlook renders with Word: no flexbox, rounded corners or gradients, so white text on a gradient vanishes; tables, solid colours, literal values, a full document, and under ~102 KB for Gmail
• Graph /me/sendMail — From is always the signed-in usergotchas / graphDelegated Mail.Send can't impersonate; configure Reply-To instead
• Opening a pre-filled e-mail — with an attachment — in the user's desktop Outlookgotchas / spfxNo API tells you which mail client is default; mailto: reaches it but carries no attachment, and a .eml needs X-Unsent: 1 or it opens read-only
• window.open with noopener returns null even when the tab opened — so your fallback runs every timegotchas / spfxCode that reads null as "blocked" runs its fallback every time: the e-mail opens twice (Outlook on the web and mailto:), the print window stays empty; open without the feature and set w.opener = null