investigate greylist for domain (mail-in-a-box and sendgrid used)

Hello there, I'm a Senior Linux System Administrator with more than 10 years experience on linux/unix systems. I've been working more than 5 years in the web hosting industry so I'm familiar with websites, CMS software, hosting servers, malware and anything else related to that. I have very good experience with cPanel/WHM, Plesk, Virtualmin/Usermin/Webmin, CWP, ISPConfig and other web panels. I also have good experience with apache, nginx, haproxy, varnish, docker, ftp, mail etc I'm pretty sure that I'll be able to help you with your project. If you have any questions please contact me. Kind regards, Bogdan Stoica

I have over 17 years computing experience and enjoy keeping up with new technologies and the latest trends. I've also led projects for big infrastructure implementations. I have good to advanced knowledge of using the following systems and services: Technologies: MS Windows Server 2012/16 Linux (CentOS,Ubuntu) MS Exchange Server 2010/12/16 Office 365 Plesk, cPanel (WHM) SonicWall Firewall, Cisco, Fortigate, Sophos Ubiquity WiFi, Unifi VPN Tunnels Network Load Balancing and High Availability IIS, Apache, Tomcat DNS Server MAC OS Citrix XenServer, Microsoft Hyper-V, VMware MSSQL, MySQL Exim, Postfix, PowerMTA Elastix, Asterisk, PBX technologies Backups - Symantec, Veeam, Nakivo Web Hosting and reselling Clouding AWS, Azure Zabbix Infrastructure planning and development Infrastructure monitoring Services - Web server, mail server, Proxy server, virtual hosting, SQL server, FTP server, VPN server (under Unix or Linux OS or Win*) , VoIP