Configure Mail Retrieval for Outlook and AOL
I'm assuming you have a functional and active email account for both the services. We'll configure both sending and receiving emails through a step-by-step process. As I mentioned earlier, you'll need login credentials for these accounts to ensure the configuration is completed successfully. So, let's first configure automated retrieval of emails for both these accounts.Step 1: Open you Gmail account and go to 'Settings → Accounts and Import → Check mail from other accounts (using POP3):' option. Click the 'Add a POP3 mail account you own' option within this section.



Step 5: If you're using a custom AOL email address, here's how you can configure automated email retrieval. Follow step 1 and 2 and type your custom AOL email address in the relevant field as already shown above in step 2.
Step 6: Whether you enter a classic AOL email address or a custom domain email address supported by AOL service, Gmail smartly detects the same and configure the right POP3 server settings as shown below. Enter the account password and make sure both the checkboxes are selected before adding your email account.


Clicking this option will instantly trigger the email retrieval process and if a new email has arrived in your Outlook or AOL account, it will be pulled in your Gmail inbox quickly.
Configure Email Sending Using AOL or Outlook Server
And now it's time to configure easy sending of emails using AOL and Outlook servers right from within a Gmail inbox. As I mentioned before, the receiving end will have no idea about the actual origin of the email (Gmail inbox). We'll first start with AOL email sending configuration.Step 1: Once inside your Gmail inbox, go to 'Settings → Accounts and Import → Send mail as:' option.
Step 2: Once in this section, click the 'Add another email address you own' option. Activating this option will open a dialogue box asking for the email address as shown below. Enter your AOL email address and uncheck the 'Treat as an alias' option. Unchecking it is very important to make sure you do not miss it.


Configuration steps for Outlook email account are as follows:
Step 1: Follow the step 1 and 2 of AOL email configuration process explained above.
Step 2: After clicking the 'Next Step >>' button, you'll get a dialogue box as shown below.

Once the configuration for both the email accounts has been completed, you can use them at will, whenever required. Now, whenever you compose an email, you'll get a drop-down menu for the 'From' field to choose one of the configured email addresses as shown below.

Wrapping It Up
Retrieving and sending emails to external email platforms is very much possible within a Gmail account. All, you need to do is to configure the necessary settings to kick-start the process. After completing the configuration, you can also create filters to apply specific labels to incoming or outgoing emails associated with a specific Outlook and AOL account. This can help you segregate them easily on an automated basis.If you're leaving a copy of all the emails on the parent server, make sure you log-in to the respective account every 3 or 4 months to clean your Outlook or AOL inbox. So, that completes the simple and easy process of managing emails of your Outlook and AOL email accounts right from within your Gmail account.