Quickbooks is unable to send invoices is a magnificent platform which enables you to make reports, keep a tack of your transactions and create or generate invoices and send them through email. But sometimes you are unable to send the invoices.
Whenever this issue arises you are unable to send invoices using QuickBooks, which you were able to send initially. It consistently shows the message “503 service is temporarily unavailable”. On closing this pop up, it may show you ‘unable to send & QuickBooks is unable to log into the server’ message.
Some of the possible reasons for happening of this issue can be:
• Email preferences may be set incorrectly.
• QuickBooks installation may be damaged.
• Domain admin may be blocked.
• Your email provider may have set account security settings.