This is so weird. I have a FileMaker database that I’ve been using for years to send out party invitations to my friends, but now I’m getting a black background in all of my outgoing emails.
A side effect of upgrading to Safari 5 (or Mac OS 10.6.4, which includes Safari 5) is that attachments sent to Mail from any application (such as FileMaker Pro, Microsoft Word, or a custom AppleScript) will now give you a black background in your outgoing email messages that makes your text unreadable. Apple is aware of this issue and will hopefully resolve this in a future software update. But for now, there are four workarounds.
If you don’t care about the hyperlinks or the formatting of your message, you can change your email to plain text by choosing Format > Make Plain Text.
Seeing this strange black background when you try to send an email message with Mail? There are several ways to fix it.
If you need to keep the formatting intact for your message, click anywhere in the body of your Mail message, choose Edit > Select All (Command-A), then Edit > Cut (Command-X), then press Delete on your keyboard to clear the leftover elements in your message. Finally, choose Edit > Paste And Match Style.
If you’d rather not go through that hassle for each one of your outgoing messages, install the excellent Mail Attachments Iconizer ($15, lokiware.info), which gives you an unprecedented amount of control in handling Mail attachments and also conveniently works around this bug.
And of course, your final option would be to switch to a different email application altogether, such as Microsoft Entourage.