One of the most common ways of transmitting computer viruses is through file attachments. To help protect you and your recipients against computer viruses, Outlook blocks the sending and receiving of certain types of files (such as .exe and certain database files) as attachments.

In Outlook, you can create one or more personalized signatures for your email messages. Your signature can include text, links, pictures, and images (such as your handwritten signature or a logo). Start guided support. Or, select a tab option below for the version of Outlook you're using.

You can reduce the file size and save disk space by compressing pictures in your document. The compression options reduce both the file size and picture dimensions based on how you intend to use the picture, such as viewing on screen or in an email message.

Like its predecessor Windows Vista, Windows 7 provides the Windows ReadyBoost function to provide Netbooks or older PC systems with more memory. You can use non-volatile flash memory such as current USB memory stick or SD memory cards to improve the performance of your system.

If you use an Microsoft 365, Exchange, IMAP, or Outlook.com account, a copy of your mailbox is stored in an Offline Outlook Data File (.ost). To reduce the size of your Outlook Data File (.pst) or Offline Outlook Data File (.ost), you can manually compact the data file.