shopz wrote:
550 Sender verify failed
ukr.net is probably applying very strict sender verification rules. You may have to change a few things about your mail server setup in order to get past their spam filters.
1. Whose address is in the "From" field of your outgoing messages? If it's your own Hotmail/Gmail/etc. address, the recipient might reject it because your Linode is not authorized to send e-mail on behalf of Hotmail/Gmail/etc. addresses. Try using an address at your own domain. Also make sure that you have an SPF record at your domain, explicitly permitting your Linode to send e-mail on behalf of it.
2. What does exim think its hostname is? This needs to be a fully qualified domain name (preferably a subdomain of your own domain) that actually points to your Linode's IP address.
3. Do you have a proper Reverse DNS entry for your Linode's IP address? (The default members.linode.com entry is fine.)
Note that it can take a few hours to a couple of days before DNS changes take effect.