Tag: Office 365

How to prevent WINMAIL.DAT attachments in Exchange Online by disabling TNEF

I’ve run into this problem a handful of times over the last few years. An Exchange user sends and e-mail with attachment(s) to a non-Exchange user and the recipient receives nothing but a WINMAIL.DAT file that they cannot open. The most commonly preached resolution was simply to tell the sender to stop using the Rich Text Format (RTF) when sending…

Granting Mailbox Permissions via PowerShell – Office 365 / Exchange Online

A few months ago while troubleshooting an Exchange issue for a client running in Office 365, I realized that my account (an Exchange Online administrator) did not have administrative access to the mailboxes through the OWA in this environment. Luckily, I came across a great article on TechNet. A few Office 365 PowerShell commands later, we were back in business. A…

There is a new Petya (but not really Petya) ransomware variant eviscerating machines globally...What can you do?