45. Outlook is adding a winmail.dat file to my sent mail

Change the your message format to plain text format or a format that the recipient's e-mail client recognizes.

http://support.microsoft.com/?id=269186

46. I can't open a hyperlink in an email.

Repair your file associations:
http://support.microsoft.com/default.aspx?scid=kb;en-us;257464

47. All my emails are blank

Try going to START > RUN and typing in regsvr32 inetcomm.dll
The body of your email should reappear.

48) Is it possible to send an email to a group of recipients so that each recipient only sees their own address?

Put all Recipients in the BCC field and your own address in TO field.

49. I'm using Word as Mail Editor and my HTML Mails have double spaced lines.

Go to Format > Paragaraph and find the "Spacing" section. Set both the before and after drop down lists to '0'.
In Outlook 2003: Select the paragraph which you want to change to single space. Click on Format > Style > Normal; Use Enter+Shift instead of Enter.

50. How can I insert an image in my Signature?

In Outlook go to Tools > Options > Mail Format > change default mail format here to HTML > OK.
Again in Outlook go to Tools > Options > Mail Format > Signatures > New > give it a name > Next. This will bring up a window where you can edit your signature.
Here type in whatever text you want.
Right Click inside this window.
Choose Insert Image and Browse to select a picture file to insert.

51. I get a New Message alert (unopened envelope icon in my toolbar) but when I launch Outlook there is no new mail in the Inbox.

Do you have the Rules Wizard set to move specific messages to other folders and mark them as read?
If you do then the icon remains in the Taskbar System Tray but in the folder it is marked as read.
Also check that you have no Custom View in your inbox that might cause this.

52. My mail is deleted from the MailServer after I download it with Outlook using POP3.

You can modify your account properties to leave a copy on the server.
Tools > E-mail Accounts > View or change existing e-mail accounts > Next
Select your account and click Change, then More Settings.
Click the Advanced tab and put a check in the "Leave a copy of messages on the server" box.

53. How do I reset (delete old entries from) Automatic Name Checks?

You can delete a single entry by scrolling through them and pressing DEL.
To remove all, search for the files with the extension of .NK2. Once you find them, rename the file that has the name of your profile (say profilename.NK2 to Profilename.old ).
This should reset the Automatic Name Check.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q287623

54. Autocomplete (completing an email address) doesn't work.

Go to Tools > Options > Email Options > Advanced Email Options to see whether the options for checking names and completing names (Autocomplete) are even turned on.
If they're turned on and it doesn't work try creating a new User Profile.

55. Some of the names show up automatically in "To:" when I type in a few letters but some of the names don't show up at all even though they are in Contacts.

Autocomplete does not use Contacts data. It uses a cache created from messages you have sent.