What the receiver is telling you

The recipient's mailbox has no space and the receiver is asking you to try again later. Gmail uses this code because the quota might be cleared; in practice a Gmail account that is over its 15 GB has usually been abandoned, and a Workspace account that is full belongs to someone who is not reading mail. Your sending tool will retry on its own schedule. If the retries keep failing, the address is dead for practical purposes.

How to handle a soft bounce

Your server or sending tool retries soft failures automatically, usually for one to three days. Most clear on their own. The mistake is leaving an address that soft-bounces on every step in an active sequence: each attempt is logged, and a mailbox that has been full or unreachable for two weeks is not going to read a follow-up. Three consecutive soft failures is the point to remove it. Track soft bounces separately from hard ones; they are a different signal and receivers weight them differently.

What to do

1. Let the tool retry for two or three days.
2. After three consecutive over-quota deferrals, remove the address.
3. Track it as a soft bounce; it is not a hard bounce for reputation purposes.

don't Do not keep the address in active sequences for weeks. A permanently full mailbox generates a bounce on every step.

Decode the whole bounce

Paste the complete failure notice — every code and the receiver's wording — and get each part explained together.

Common questions