Sometime our email are incorrectly identified as spam. To prevent that from happening, it's best if you add Mendeley to your safe sender list or address book. Here's how it works:
Gmail (Google Mail)
Open the email and click on the little arrow next to "Reply" and click on "Add Mendeley to Contacts list".
Open the email and click on "Actions" in the menu bar, then click on "Junk E-mail" and select "Add Senders Domain (@example.com) to Safe Senders List". Enter "mendeley.com" as a safe sender domain.
Log in to Hotmail and click on "Options" (top-right corner) and "More options...". In the section "Preventing junk email" click on "Safe and blocked senders", then click on "Safe senders". In the dialog box type in "mendeley.com" and click on the "Add to list" button. To get back to your inbox click on "Go to inbox" in the top-left corner.
If your email provider is not listed here, please contact your email provider's customer support.