Does'n send backup

Errors in log file

[31-Mar-2016 18:30:56 UTC] PHP Warning: mysqli::mysqli(): Headers and client library minor version mismatch. Headers:100023 Library:100106 in /home/xxxxxxx/public_html/xxxxxxx/wp-content/plugins/all-in-one-wp-security-and-firewall/admin/wp-security-database-menu.php on line 547
[31-Mar-2016 18:30:56 UTC] WordPress database error Table 'xxxxxxx.wp_term_taxonomy' doesn't exist for query SELECT term_taxonomy_id FROM wp_term_taxonomy WHERE term_id=6 AND taxonomy='nav_menu' made by include('wp-admin/admin-footer.php'), do_action('admin_footer'), call_user_func_array, iclNavMenu->_set_custom_status_in_theme_location_switcher
[31-Mar-2016 18:30:56 UTC] WordPress database error Table 'xxxxxxxxxxx.wp_term_taxonomy' doesn't exist for query SELECT term_taxonomy_id FROM wp_term_taxonomy WHERE term_id=0 AND taxonomy='nav_menu' made by include('wp-admin/admin-footer.php'), do_action('admin_footer'), call_user_func_array, iclNavMenu->_set_custom_status_in_theme_location_switcher
[31-Mar-2016 18:30:56 UTC] WordPress database error Table 'xxxxxxxxx.wp_options' doesn't exist for query UPDATE <code>wp_options</code> SET <code>option_value</code> = '1459450856' WHERE <code>option_name</code> = '_transient_timeout_2__974818834' made by A_MVC_Router->cache_lookups, C_Photocrati_Transient_Manager::update, C_Photocrati_Transient_Manager->set, set_transient, update_option

Hi, reading the log file above is letting you know that there is some issues with your database? Can you confirm that your database is working correctly without any issues? The log file is also pointing to your theme header and taxonomy settings.

Database and theme works without any problem.

As we research in cooperation with server support, all these errors was caused by PHP 5.6 version. There is no more errors, after we turn to PHP 5.5. But, server support doesn’t know, why your plugin doesn’t send the backup to the mailbox.

What is the size of your backup file? Do you have any limitations set up if the backup file is too large in your mailbox settings?

Size of backup file – 1.6 mb.
There is no file size limitations in mail.com
I get more than 3mb backup files from other websites(same hosting).

When you created a backup did you create a manual backup or an automatic backup?

Can you check the log file located in Filesystem Security -> Host System Logs?