It’s not your imagination. You are getting more spam in your e-mail inbox.Symantec, which focuses on Internet security and storage, issued a report this week that said a stunning 90.4 percent of e-mail on corporate networks this month was unsolicited. That’s a 5.1 percent jump over April.The report highlights:• Spam – 90.4% in May (an increase of 5.1% since April) • Viruses – One in 317.8 emails in May contained malware (a decrease of 0.01% since April) • Phishing – One in 404.7 emails comprised