Email tests addressing, composing, replying, forwarding, attachments, folders and safety. CCC questions often hinge on the difference between To, Cc and Bcc, or on what happens when you reply to all.
Core rules
- An address is
local-part@domain, e.g.[email protected]. The domain is not case-sensitive in normal use; the local part may be. - To is the primary recipient; Cc is a visible copy; Bcc is a hidden copy. Bcc recipients do not see one another.
- Reply goes to the sender; Reply All goes to the sender plus all visible To and Cc recipients; Forward sends the message to a new recipient.
- SMTP sends mail; POP3 and IMAP retrieve it. IMAP keeps folders synchronised across devices; POP3 often downloads to one device.
- Attachments should be within the provider’s size limit; large files are better shared by link.
Worked example
You receive a message sent to [email protected] with [email protected] in Cc and [email protected] in Bcc. You choose Reply All. Your reply goes to the original sender and the Cc address, but not to the Bcc address, because Bcc recipients are hidden. If you want the auditor to see your reply, forward it separately or add the address explicitly.
Traps
Do not put a large mailing list in To when privacy matters; use Bcc. Reply All can send an unintended message to a whole group. An attachment is not the same as a link; deleting an attachment from a received message may not delete the stored file. Treat urgent requests for passwords or OTPs as phishing until verified through an independent channel.