Voting buttons stay inside classic Outlook.
Outlook can attach Approve, Yes, or a custom vote to a message. The recipient votes inside Outlook, and you read the responses on the sent message. Gmail has no Vote menu, so a recipient there does not get a working vote.
What Outlook voting buttons is
Voting buttons are part of classic Outlook for Windows. Microsoft's help requires a Microsoft Exchange Server account. On the Options tab you pick Approve;Reject, Yes;No, Yes;No;Maybe, or custom names separated with semicolons. The recipient votes from the Reading Pane or the Vote command. You open the sent message, usually in Sent Items, and select Tracking. Tracking does not appear until someone has voted, and you can copy the table into Excel. Microsoft's feature comparison lists voting buttons as available in classic Outlook and not supported in the new Outlook. Adding them is listed as Yes for Outlook for PC and No for Outlook on the web, Outlook for iOS, and Outlook for Android. The Windows and Mac comparison lists them as No on Mac. An encrypted message, or one with Information Rights Management permissions, does not show the buttons. Outlook's Poll is a different insert, and this page is not about that.
What Easy Reply is
Easy Reply is a Chrome extension for Gmail. You add one question and two to four answers to an email you are already writing. The recipient does not install an add-in and does not need an Outlook or Easy Reply account. They click an answer. The choice comes back on the thread, and it shows in Insights. Easy Reply does not fill an Outlook Tracking tab or export a vote table to Excel.
Side by side
Where you add it
Easy Reply. In the Gmail you are already composing.
Outlook voting buttons. In classic Outlook for Windows, on the Options tab, with an Exchange account. Not supported in the new Outlook. Adding them is No on the web and on mobile. Outlook for Mac lists voting buttons as No.
Who can answer
Easy Reply. Anyone who can click the button. They do not install Easy Reply.
Outlook voting buttons. Someone voting in Outlook, from the Reading Pane or the Vote command. A recipient in Gmail does not get that menu.
Where the answer goes
Easy Reply. Back on the email thread, and into Insights.
Outlook voting buttons. The Tracking view on the message you sent. You can copy that table into Excel.
What it will not do
Easy Reply. An Exchange tracking table, or a tally you export to Excel.
Outlook voting buttons. A working vote for someone reading the message in Gmail.
When to use Outlook voting buttons
Use Outlook voting buttons when you send from classic Outlook for Windows on Exchange, the recipients can vote in Outlook, and you want the Tracking table. Easy Reply will not replace that tally.
When to use Easy Reply
Use Easy Reply when you are writing in Gmail, or when the recipient will not see an Outlook Vote menu. Yes, no, maybe, approve, or reject. They click once. You see the answer on the thread.
FAQ
Do Outlook voting buttons work in Gmail?
No. The recipient votes inside Outlook, from the Reading Pane or the Vote command. Gmail has neither. Sending the buttons to a Gmail address does not recreate them there, and you cannot insert them while composing in Gmail.
Where do Outlook voting responses show up?
Open the original message, usually in Sent Items, and select Tracking. Microsoft says that view does not appear until at least one person has voted. From there you can copy the names and responses into Excel.
Can I use voting buttons in the new Outlook or on a phone?
Microsoft lists voting buttons as not supported in the new Outlook, and as No in Outlook for Mac. Adding them is listed as No for Outlook on the web, Outlook for iOS, and Outlook for Android. Classic Outlook for Windows is the client their help walks through.
Free for 50 sends a month. The other person does not install anything.