Unfortunately, mail senders can be easily forged. Mails behave almost like postcards here. Anyone can write any sender on a postcard and post the card in a post box. The post office delivers the postcard. Your mail server generally accepts all mails addressed to you and delivers them. Spam filters do the rest to filter out advertising mails. A well-made fake mail cannot be filtered out by spam filters.

If you think an e-mail is a fake, you can look at the Internet headers of the e-mail. Each mail consists of the actual message and additional metadata is documented in the Internet headers.

Here are a few tips on how this can be displayed in different mail systems:

• As of Outlook 2007, you can find this in the File, Properties menu. Microsoft explains this in detail in this link.
• Thunderbird Mail uses the keyboard shortcut CTRL + U to display the currently selected mail in the source text, including Internet headers.
• Apple Mail uses the keyboard shortcut Shift + Command + H or the menu View, Mail, All headers.

In the Internet headers you will find the mail servers via which this mail was delivered; you can compare these servers with another mail from the sender. In addition, times are also displayed - often marked with other time zones - when the mail was accepted and where it was forwarded.

Your administrator will certainly be able to help you check the mail headers.