Microsoft Outlook, a part of office suite is a personal information manager used particularly for emails. It also includes other applications like contact manager, note taking, calendar, task manager, journal and more. A user can use it as a stand-alone application or with Microsoft SharePoint server and Microsoft Exchange Server. Its different versions are available for Windows, Mac, iOS and Android operating system.

Outlook also allows the users to add personalized signatures for the email messages. This helps the users to draft an email without adding their signatures every time in it. Apart from text, you can also add images, logo of your business, electronic business card and even an image of your handwritten signature. You can further choose from two options while adding a signature. This includes adding them automatically to all outgoing emails or choosing which messages include a signature. To add your signatures, follow the below mentioned steps (for Outlook 2016 and 2013):

1. Login to your Outlook account
2. Compose new email
3. On the message tab, under the Include group, select Signature -> Signatures
4. Under Select Signatures to Edit, select New
5. In the New Signature dialogue box, enter the text for your signatures
6. Type the signature under Edit Signature
7. Now, set the below mentioned options for your signature under the tab “Choose default signature”
• E-mail account list- Select an email account to link with the signature. You can keep different signatures for each email account
• Replies or Forward list- Select the signature (auto-sign) you want to add automatically to the outgoing messages (reply and forward both). Or accept the default option, i.e. None
• New message list- Select the signature you want to add automatically to each mail. If you want to add that signature in particular emails, then choose None
8. Now, choose Ok to save your message

For adding an image or logo to your signature, follow these steps:
1. Open a New Message
2. Choose Signatures from Signature
3. Under Select signature to edit box, select the logo or image of the signature you want add
4. Choose the image icon and locate your image
5. Now, select Insert
6. You can resize your image by right-clicking the image and selecting Picture
7. Choose the size tab and use the different options to resize the image
8. Make sure to keep the Lock aspect ratio checkbox checked
9. Select Ok, if you are done!

This will go perfect if you don’t want to automatically add the signature in every email, reply or forwards. Follow these steps to add a signature manually:
1. In the email message, in the Include group on the ribbon
2. Choose Signature
3. Now, select your signature from the fly-out menu
4. If you have multiple signatures, you can choose any one of them

Still, if you find any kind of technical glitches while performing this contact with Outlook Customer Support.

Source: http://help-number.com/blog/how-to-create-and-add-a-signature-to-your-message-in-outlook/