Originally Posted by comfort central
I've been getting intermittent 553 errors with Questmail in last two days, no changes to mail client...
We may need some more information and clarification -- I'm confused about whether you're seeing the errors when actually using QuestMail
(FutureQuest's web-based email) or when using your own email client/software (as you say "no changes to mail client"). Is it happening when trying to send to a specific address?
Usually 553 errors are a result of one of two things: