Thanks for your replay,
Our php server settings, now, are:
memory_limit: 256
max_execution_time: 240.
It's not working, this is the message in the crawler tab:
Updated on 2016-04-11 16:11:11 (31 seconds ago) , Time elapsed: 0:00:15,
Pages crawled: 27329 (27329 added in sitemap), Queued: 0, Depth level: 2
Current page: sitemap_it.xml (1.3)
27329 added in sitemap... the script get all the info but it doesn't end properly.