trigger confusion

[Datacenter1.com]

Greetings

I'm new with Zabbix and I trying to set to a simple trigger like:
{Host.Standalone:smtp.last(0)}<1
But I want the trigger true after two consecutive failures or after x seconds down

How can I do this?

Thanks in advance

[btriem]

use max instead of last. i.e.

{Host.Standalone:net.tcp.port[80].max(300)}<1


300 is in seconds.

[Alexei]

Thie is for ZABBIX 1.1beta10 or higher:

{Host.Standalone:smtp.max(#2)}=0

{Host.Standalone:smtp.max(300)}=0