To, Cc, Bcc and Reply-To: which one, and when

Most people use To and Cc by habit and meet Bcc and Reply-To only when something goes wrong. A shared inbox such as info@ or orders@ raises the stakes, because several people answer and a customer sees all of it.

To: who must act

Put in To the people you expect to do something or answer. If you write to a customer, the customer goes in To. Everyone in To sees everyone else in To and Cc.

Cc: who should know

Cc is for people who need to see the message but are not expected to reply. It is easy to overuse. When a message copies six people, each assumes someone else will answer.

Take Alpenhof Trading, who write to orders@aegeanfreight.example about a delayed container. The customer is in To. Cc the account manager only if the customer should know that person is involved. If only your own team needs to know, there are better ways, covered below.

Bcc: who must not be seen

Everyone in Bcc receives the message, and nobody else sees their address. It has two honest uses:

1. 1

   Writing to a group of people who do not know each other, such as a notice to several customers at once, so their addresses stay private.

2. 2

   Moving yourself out of a thread: Cc the person you are handing over to, move yourself to Bcc, and tell the others in the message that you are stepping aside.

Take care with Bcc. A person in Bcc who presses Reply all answers everyone in the visible list, and that shows they were there. Bcc is not for hiding things from the people you are writing to.

In DMU Mail, choose Cc/Bcc in the composer to open the fields. On mail you sent, the message details show a Bcc line marked "Hidden from the other recipients", so you can see who was copied.

Reply-To: where answers go

Every message has a sender, and it can also name a different address for replies. That is Reply-To.

It is how a shop's order system sends a receipt from an address nobody watches and still gets your answer at its support team. It is also how a mailing list keeps replies on the list. Pressing Reply goes to the Reply-To address, not to the sender's.

Because it can send your answer somewhere you did not expect, Reply-To is worth a glance on mail you do not trust. A scammer can use it to take the conversation to an address that is not the one on the From line.

What DMU Mail does with it

• Reply goes to the Reply-To address a message names, and Reply all includes it. This has been so since the release of 12 October 2026.

• In a message's details, a Reply-to line appears only when it differs from the sender, so an ordinary message has no extra line to read.

• The Assistant's "Is this email safe?" check, when your organisation has the Assistant on, mentions a Reply-To that points elsewhere.

You can choose what the r key does, Reply or Reply all, in Settings › Writing, under Default reply.

For a shared inbox

Here is how this plays out for a team answering orders@.

• Answer the customer in To, from the shared mailbox, so the reply is part of the same conversation for everyone.

• Do not Cc colleagues to tell them you have it. Assign the conversation instead, so the list shows who has it.

• Do not Bcc colleagues to keep them in the loop. They can already see the conversation, and team chat is where you talk about it. The customer never sees team chat.

• Use Reply all only when everyone on the thread needs the answer.