How Billdu sends emails
Mobile app - emails are sent from your own mail app (Gmail, iOS Mail, etc.) and appear in your Sent folder
Website - emails are sent from invoices@mail.billdu.com with your business name in the sender field; replies go to your account email address
Knowing which method you use helps you find the right fix below.
Most common reasons an email isn't delivered
The client's email address on the invoice is incorrect or has a typo
The email landed in the client's spam or junk folder
The client's email provider blocked the message due to security filters
Your mail app on mobile is not set up correctly, so the email never left your device
The invoice was shared or exported as a PDF but not actually sent via email - check the document status
What to check first
Open the invoice and check its status in the Timeline - "Sent" means the email left Billdu; "Unsent" means it was never sent
Verify the client's email address on the invoice - even a small typo causes a bounce
Ask your client to check their spam or junk folder
What you can do
Resend the invoice using the Send button inside the invoice
Share the invoice as an online link - your client can open and pay it directly without email
Send the invoice as a PDF via WhatsApp, SMS, or any other messaging app
Change the default email text and subject line under Settings - Client communication - this reduces the chance of messages being filtered as spam
On mobile, go to Settings - Client communication - Email settings and turn off "Send with iOS mail" or "Send with mail app" to use Billdu's mail server instead
If the send button is greyed out or you get an error on mobile
Your mobile mail app is not configured correctly
Go to Settings - Client communication - Email settings
Turn off "Send with iOS mail" or "Send with mail app" - Billdu will send emails from its own server instead
Alternatively, set up your iOS or Gmail app correctly on your device
Tip: To make sure your client always has the invoice, enable "Attach document as PDF" in Settings - Client communication - Email settings. The PDF is then included directly in every email you send.
Didn't find what you were looking for? Contact our support team, and we'll sort it out for you.