Yesterday i was trying to send an email on my iPhone, and i got an error saying that it cant send my email, as the email address was invalid.

i never set mail up on the phone, it synced itself with my mac. Its a TPG email account if that makes a difference.

how do i fix the error?

Check SMTP settings.

Check the 'To' field to see whether it is a valid email address i.e. username@hostname.com (or whatever, edu.au, gov.au, etc).

wouldnt it have imported the smtp settings from mail on my computer? it send email fine

If it sends email fine, then what is the problem?

Sounds like they OP is trying to send email via the TPG email server when he or she is not on an IP address which TPG believe them to be a customer.

As such the mail server indicates a relay denied, and generates an error that the OP might be confusing.

OP: Is your outgoing mail server configured to that of the TPG smtp server, and were you trying to send email to this server while using your mobile's 3G data connection at the time?

A few people had this issue before when the 3G iPhone came out.

It was related to Gmail/TPG as well and 3G usage.

Set up authentication or use/add another SMTP server.

My Bigpond email on my iPod Touch is doing the same; receiving email, but not sending any. The settings imported straight from Mac Mail (which obviously works), but the iPod Touch Mail still doesn't send. Strange?

Use outgoing server authentication, or your carrier's SMTP details.

sorry,

my computer sends emails fine. my iphone wont send them at all.

This happened when i was at home, using our wireless connection (was trying to send a photo). Never tried on 3G, as am usually near a wireless network.


How do i use outgoing server authentication, or your carrier's SMTP details?

Look inside the Settings for Mail.

Find out from TPG's support pages for the rest e.g. SMTP.