Exhibit 99.3

Text of Customer Email to announce Harris/Constellation Acquisition

October 2, 2012

Notice to Investors

The tender offer for the outstanding common and preferred stock of the Company referred to in this communication has not yet commenced. This communication is neither an offer to purchase nor a solicitation of an offer to sell any securities. The solicitation and the offer to purchase shares of the Company’s capital stock will be made pursuant to a Tender Offer Statement on Schedule TO (including the Offer to Purchase, the related Letter of Transmittal and other related materials) that N. Harris Computer Corporation and NHCC Merger Corp. intends to file with the Securities and Exchange Commission (the “SEC”). At the time the offer is commenced, N. Harris Computer Corporation and NHCC Merger Corp. will file a Tender Offer Statement on Schedule TO with the SEC and, thereafter, the Company will file a Solicitation/Recommendation Statement on Schedule 14D-9 with respect to the offer. Investors and security holders of the Company are urged to read these materials (including the Tender Offer Statement on Schedule TO, the Offer to Purchase, the related Letter of Transmittal and the Solicitation/Recommendation Statement on Schedule 14D-9) (when they become available) carefully in their entirety since they will contain important information. Investors and security holders may obtain free copies of these materials (when they become available) and other documents filed by the Company with the SEC at the website maintained by the SEC at www.sec.gov. Investors and security holders may also obtain free copies of the documents filed by the Company with the SEC by contacting: David B. Dechant; Chief Financial Officer; Computer Software Innovations, Inc.; 900 E. Main Street, Suite T; Easley, South Carolina 29640

Forward-Looking Statements

This communication contains forward-looking statements that are not historical facts and are subject to risks and uncertainties that could cause actual results to differ materially from those described. These statements may be identified by such forward-looking terminology as “expect,”

“achieve,” “plan,” “look,” “projected,” “believe,” “anticipate,” “outlook,” “will,” “would,” “should,” “intend,” “potential” or similar statements or variations of such terms. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. Forward-looking statements in this communication include statements regarding the anticipated benefits of the transaction; statements regarding the anticipated timing of filings and approvals relating to the transaction; statements regarding the expected timing of the completion of the transaction; statements regarding the ability to complete the transaction considering the various closing conditions; any statements of expectation or belief; and any statements of assumptions underlying any of the foregoing. All forward-looking statements are based largely on current expectations and beliefs concerning future events, approvals and transactions that are subject to substantial risks and uncertainties. Actual results could differ materially from those currently anticipated due to a number of risks and uncertainties. Risks and uncertainties that could cause results to differ from expectations include: uncertainties as to the timing of the tender offer and merger; uncertainties as to how many of the Company’s shareholders will tender their shares in the offer; the risk that competing offers will be made; the possibility that various closing conditions for the transaction may not be satisfied or waived; the effects of disruption from the transaction making it more difficult to maintain relationships with employees, customers and vendors; other business effects, including the effects of industry, economic or political conditions outside of the Company’s control; transaction costs; actual or contingent liabilities; and other risks and uncertainties discussed in documents filed with the SEC, including the risks and uncertainties included under “Risk Factors” and “Forward-looking Information” in our Annual Report on Form 10-K for the year ended December 31, 2011, and other periodic reports filed with the SEC which are incorporated herein, as well as the Tender Offer Statement on Schedule TO to be filed by N. Harris Computer Corporation and NHCC Merger Corp. and the Solicitation/Recommendation Statement on Schedule 14D-9 to be filed by the Company. These forward-looking statements speak only as of the date of this communication and the Company does not assume any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or developments or otherwise, except as required by law.