In outlook, you can easily reply an email easily as follows:

If you are used to reading emails in the reading pane, you can select the email you will reply in the message list, and then click Home > Reply to reply the sender only, or click Home > Reply All to reply to the sender and all recipients together.

If you prefer to reading emails in the message window, you can click Message > Reply to reply the sender only, or click Message > Reply All to reply to the sender and all recipients simultaneously.

To work more efficiently, some users would like to apply keyboard shortcuts in Outlook. We also can use keyboard shortcuts to quickly reply emails in Outlook.

After selecting the email in the message list or opening the email in the message window, we can:
A. Press Ctrl + R keys together to reply the selected or opening email to the sender only;
B. Press Ctrl + Shift + R keys together to reply the selected or opening email to the sender and all recipients in the To and Cc fields.

By default, when replying to an email, the replying message includes the original message without indent. However, we can configure the replying options and change the replying settings as we need.

1. Click File > Options to open the Outlook Options dialog.

2. In the Outlook Options dialog, click Mail in the left sidebar, go to the Replies and forwards section, and select an option from the When replying to a message drop-down list.

3. Click the OK button.

Notes:

(1) If you select Do not include original message from the When replying to a message drop-down list in the Outlook Options dialog, the replying message will be created without any message content.

(2) If you select Attach original message from the When replying to a message drop-down list in the Outlook Options dialog, the original message is added as an attachment in the replying message.

(3) If you select Include original message text from the When replying to a message drop-down list in the Outlook Options dialog, the original email (including both message body and message header) will be added into the replying message’s message body.

(4) If you select Include and indent original message text from the When replying to a message drop-down list in the Outlook Options dialog, the original email (including message header and message content) will be added to the replying message’s message body with left indent.

(5) If you select Prefix each line of the original message from the When replying to a message drop-down list in the Outlook Options dialog, the original email (including message header and message content) will be added into the replying message’s message body, and a prefix blue vertical line is also added at the leftmost of the content.

Since Outlook 2013, when we read and reply an email in the reading pane directly, the replying message is embedded in the reading pane automatically. Some Outlook users may need to pop out the replying message in a new window. Here, this section will show you the solutions to pop out one or all replies in message windows.

4.1 Pop out one replying message

When a replying message is embedded in the reading pane, we can click the Pop Out button at the top-left corner of the reading pane to open the replying message in a new message window directly.

4.2 Always pop out all replies

You can also configure the Outlook options to always pop out the replies in new message windows automatically.

1. Click File > Options to open the Outlook Options dialog.

2. In the Outlook Options dialog, click Mail in the left bar, go to the Replies and forwards section, and tick the Open replies and forwards in a new window option.

3. Click the OK button.

From now on, all replying messages will be opened in new message windows automatically in Outlook.

Notes:
(1) If the Open replies and forwards in a new window option is enabled, all forwarding messages will be automatically opened in new message windows too.
(2) If we open an email in the message window firstly, then reply it by clicking Message > Reply or Reply All, the replying message will open in a new window directly.

Sometimes, to distinguish the replies with other emails, says new emails or forwarding emails, we want to set different colors or font sizes for the message text in the replying message. This section will show the detailed guidance to get it done.

1. Click File > Options to open the Outlook Options dialog.

2. In the Outlook Options dialog, click Mail in the left bar, and then click the Stationery and Fonts button in the Compose messages section.

3. In the Signatures and Stationery dialog, click the Font button in the Replying or forwarding messages section.

4. In the Font dialog, we can set the font as you need:
(1) To reply with bigger or smaller text, choose a proper font size in the Size list box;
(2) To reply with different color text, just specify a font color from the Font color drop-down list;
(3) We can also set other font styles as you need, says bold, Italic, underline, caps, strikethrough, etc.

Tips: We can directly preview the text with all specified formatting in the Preview section of the Font dialog.

5. Click the OK buttons successively to save the changes and close all dialogs.

From now on, when we type in text in the replying message, the typed text will be formatted to the specified color, font size, or other font styles automatically. See screenshot:

Notes: This operation will also change the font styles and font color in the forwarding emails.

Some Outlook users notice that there is a group of quick commands on the right sidebar of the reading pane as below screenshot shown. This vertical bar let us quickly delete, move, response, or open emails as soon as possible. We can also enable this vertical bar to quickly reply emails in Outlook.

1. Click the Customize Quick Access Toolbar arrow in the quick access toolbar > Touch/Mouse Mode.

Notes:

In some Outlook versions, the Touch/Mouse Mode common does not display in the Customize Quick Access Toolbar drop-down menu. We can add the common into the quick access toolbar as follows:
1. Click Customize Quick Access Toolbar arrow > More Commands;
2. Now the Outlook Options dialog is opened with the Quick Access Toolbar enabled in the left bar. We need to (1) select All Commands from the Choose commands from drop-down list, (2) click to highlight Touch/Mouse Mode in the left list box, (3) click the Add button, (4) Click the OK button.

2. Then the Touch/Mouse Mode command is added into the quick access toolbar. Click the Touch/Mouse Mode button , and then select Touch from the drop-down menu.

Now the group of quick commands are added vertically on the right side of reading pane.

3. In the message list click to select the email you will reply, click the Response button in the rightmost of reading pane, and then select Reply or Reply All from the drop-down menu.

4. Then the replying message is embedded in the reading pane. Compose and send it as you need.

Notes:
(1) You can click Touch/Mouse Mode > Mouse Mode in the quick access toolbar to hide the group of quick commons on the right side of reading pane.
(2) In this case, if you want to pop out the replying message, please click the Pop Out button of the group of quick commands to open it in the message window.

If new emails arrive in our Outlook when we are out of office, says we are on vacation, out for lunch, etc., we can enable the automatic replies to response these email in time.

7.1 Send auto replies with Automatic Replies feature

For exchange account types, we can enable the Automatic Replies feature to response new coming emails easily in Outlook.

1. Click File > Info > Automatic Replies.

2. In the Automatic Relies Replies dialog, you need to:
(1) Check the Send automatic replies option;
(2) It is optional. Tick the Only send during this time range option, and then specify the start time and end time as need.
(3) Under Inside My Organization tab, type in the message content of the auto replies.

Notes: If we need to automatically reply to all received emails, you can enable the Outside My Organization tab, check the My Contacts only or Anyone outside my organization option as you need, and then type in the message content.

3. Click the OK button.

From now on, when we open mail folders of the specified exchange account, it will show a horizontal note below the Ribbon to remind us “Automatic Replies are being sent for this account”. And we can click the Turn off button to disable the automatic replies directly, and click the x button at the far right to hide the note.

7.2 Send auto replies with an email rule

As far as we know, the POP3 or IMAP email accounts do not support automatic replies in Outlook. If our email account type is POP3 or IMAP, we can create an email rule to enable the automatic replies in Outlook.

Firstly, we need to create an email template for the auto replies rule.

1. Create Home > New Email to create a new email, and type in the auto replying content in the message body.

2. In the new composing message window, click File > Save As.

3. In the Save As dialog, type in a name for the template, select Outlook Template from the Save as type drop-down list, and click the Save button.

Now the auto reply template is created. We can go ahead to create the auto replying rule.

4. Click Home > Rules > Manage Rules & Alerts.

5. In the Rules and Alerts dialog, under the Email Rules tab, click the New Rule button.

6. In the Rules Wizard, click to highlight the Apply rule on messages I receive option, and click the Next button.

7. In the second Rules Wizard, specify the conditions that you will filter received emails by (in my case, I tick the send only to me option), and click the Next button.

8. In the third Wizard, tick the reply using a specific template option in the Step 1 section, and then click the underlined text a specific template in the Step 2 section.

9. In the opening Select a Reply Template dialog, select User Templates in File System from the Look In drop-down list, click to select the auto replying template we created just now, and click the Open button.

10. It returns to the third Rules wizard, click the Next button.

11. In the fourth Rules Wizard, specify exceptions as need, or do not set any exceptions, and click the Next button.

12. In the last Rules Wizard, name the rule in the Step 1 box, tick running options as need in the Step 2 section, and click the Finish button.

13. In the popping out Microsoft Outlook warning dialog, click the OK button to go ahead.

14. Then it goes back to the Rules and Alerts dialog. Make sure the new created auto replying rule has been ticked, and click the OK button to close the dialog.

From now on, all new coming emails that meet the specific conditions will be replied automatically with the preset replying template.

7.3 Send auto replies by a third-party addin

This section introduces a third-party addin, Kutools for Outlook, to quick enable auto replies with preset replying content easily to one or multiple email accounts, no matter which types they are!

1. After installing Kutools for Outlook, click Kutools > Reply > Auto Reply Manager in Outlook.

2. In the Auto Reply Manager dialog, we can do as follows:
(1) Tick email accounts we will enable the auto replies for;
(2) In the Auto reply subject prefix box, type in words that will be added before the subjects of original emails;
(3) In the Auto Reply Text box, type in the auto replying content.

3. Click the OK button. Then the Auto Reply feature is enabled for the specified email accounts. From now on, when new emails come into these email accounts, they will be replied automatically with the specified replying content.

Notes: We can disable the Auto Reply feature easily by clicking Kutools > Reply > Enable Auto Reply again.

When replying to an email in Outlook, the attachments in the original email will not be added to the replying message by default. To remain attachments in the replying message, we can apply third-party addin or paste feature to get it done.

8.1 Reply with attachments by copying and pasting

To reply with attachments in Outlook, we can copy all attachments from the original email, and then paste into the replying message.

1. Click to open the email we will reply in the reading pane.

2. Right click any one of attachments, and choose Select All from the context menu.

3. Press Ctrl + C keys to copy these selected attachments.

4. Click Home > Reply or Reply All to reply the email.

5. Now the replying message is opening. Put cursor in the message body, and press Ctrl + V keys to paste the attachments. Then we will see all attachments are added into the attachment bar.

6. Compose the replying message and send it as need.

8.2 Reply with attachment by a third-party addin

We can also use a third-party addin, Kutools for Outlook, to quickly reply an email with remaining all attachments of the original email in Outlook.

1. Select the email we will reply, and click Kutools > Reply > Reply with Attachment or Reply All with Attachment.

2. Then the replying message is opening with remaining all attachments of the original email. Compose the replying message and send it as need.

When we apply the Reply All feature to reply an email to the sender and other recipients, my email address is not included as a recipient in the replying message. Here, this section will introduce two solutions to reply to all including myself.

9.1 Reply to all including me by an email rule

We can create an email rule to always Cc our replies to ourselves in Outlook to solve the problem easily.

1. Click Home > Rules > Manage Rules & Alerts.

2. In the Rules and Alerts dialog, under Email Rules tab, click the New Rule button.

3. In the Rules Wizard, click to highlight the Apply rule on messages I send option, and click the Next button.

4. In the second Rules Wizard, tick the with specific words in the subject option in the Step 1 section, and then click the underlined text specific words in the Step 2 section.

5. In the popping out Search Text dialog, type RE: in the first box, click the Add button, and then click the OK button. See screenshot:

6. Then it goes back to the second Rules Wizard, click the Next button.

7. In the third Rules Wizard, tick the Cc the message to people or public group option in the Step 1 section, and click the underlined text people or public group in the Step 2 section.

8. In the popping out Rule Address dialog, type in our email addresses in the To box, and click the OK button.

Tips:
(1) If we need to Cc the replies to multiple contacts, type in these contacts’ email addresses and separate them by semicolons.
(2) We can also click to select contacts, and then click the To button to add these contacts as recipients.

9. Then it goes back to the third Rules Wizard, and click the Next button to go ahead.

10. In the fourth Rules Wizard, specify or do not specify any exceptions as need, and click the Next button.

11. Now the last Rules Wizard opens. We can do as follows:
(1) Type in a name for the new rule in the Step 1 box;
(2) In the Step 2 section, check the running options as need;
(3) Click the Finish button.

12. In the popping out Microsoft Outlook warning dialog, click the OK button.

13. Then it returns to the Rules and Alerts dialog. Make sure the new email rule is checked, and click the OK button to close the dialog.

From now on, all replies we send will be cc to ourselves automatically.

Notes:
(1) This rule will not only Cc replies that we reply to all recipients, but also Cc replies that we reply to the senders only.
(2) Even if there are multiple email accounts in your Outlook, the rule cannot identify which email account the emails stay in, and it will Cc the replies to specified email account only.

9.2 Reply to all including me by an amazing tool

We can also use a third-party addin, Kutools for Outlook, to enable the Include myself when reply all feature, and always add my email account as a To recipient in the replying message.

1. After installing Kutools for Outlook, click Kutools > Options.

2. Now the Options dialog comes out. Enable the Reply tab, tick the Include myself when reply all option, and click the OK button.

From now on, when we select an email and click Home > Reply All, Our email address will be added as a To recipient automatically in the replying message.

Notes: If there are multiple email accounts in our Outlook, only the email account that the currently replied email stays in will be added as a To recipient in the replying message.

We usually receive emails in different message formats, and the replies inherit the message format of the original emails by default. However, we can change the message format for one replying message, or always reply emails in a fixed message format. These issues have been talked about in other topics, and click corresponding links to get the detailed information:

10.1 Change message format for one replying message:
https://www.extendoffice.com/outlook-tutorials-edit-send-emails/advanced-compose-emails/outlook-message-formats.html#a2

10.2 Always reply in Plain Text format:
https://www.extendoffice.com/outlook-tutorials-edit-send-emails/advanced-compose-emails/outlook-message-formats.html#a5

10.3 Always reply in HTML format:
https://www.extendoffice.com/outlook-tutorials-edit-send-emails/advanced-compose-emails/outlook-message-formats.html#a6

As far as we know, we can specify different signatures for email accounts, and also enable to specify different signatures for new emails and replies/forwards. Click below hyperlink to view the detailed information:
https://www.extendoffice.com/outlook-tutorials-edit-send-emails/advanced-compose-emails/email-signatures.html#insert-automatically