To jail inmate Lisa Coulter, the Hallmark card she got from a support group is a lifeline, something to hold close to her heart as she nervously waits for a judge to release her or send her back to prison after 16 years behind bars.

“Welcome home,” the card read, and “We are praying for you.” Coulter wrote back, “All the days I’ve spent holding my emotions in, being so visibly strong through this entire ordeal, came to an instant surface and I cried so hard for the better part of two hours.”

To Santa Clara County jail officials, such greeting cards and letters — no matter how therapeutic to inmates — are a security risk. Citing concerns about drugs and other contraband tucked into envelopes, hidden under stamps or painted onto sheets of paper, jail officials want all mail from friends and family to be limited to small postcards.

The restrictive mail policy — the only one in the Bay Area and the fifth in the state — was set to start June 1. But after vocal objections from community and advocacy groups, the jail this week postponed the change until at least July 1. Supporters say limiting mail to inmates would hinder rehabilitation and unfairly punish the estimated 90 percent of correspondents who don’t try smuggling. Along with the danger of contraband, authorities say too much effort goes into checking the volume of mail. Even though correspondence from attorneys would be exempt from the restrictions, the public defender’s office and inmate-rights groups also are dead-set against the change.

“It’s not right,” said San Jose resident Ramona Redmond, whose boyfriend is in county jail. “How you supposed to get everything you want to say on a postcard? What are you supposed to do, send a thousand postcards?”

Cost is another consideration: A letter costs 46 cents; a postcard is 33 cents. Phone calls must be made collect, and each 15-minute call costs $5 to $20, depending on whether it’s local or out of state.

County jails chief John Hirokawa plans to hold a community meeting to hear the concerns and present the Department of Correction’s rationale.

“The new policy is predominantly for the safety of staff and the inmate population,” he said, noting that people have tried to smuggle hypodermic needles, staples for tattooing, black tar heroin, PCP and tabs of acid through the mail. Hirokawa notes that drugs create a black market, and cause overdoses and fights between inmates and assaults on guards.

Jail officials have the administrative authority to make the change without approval from the Board of Supervisors. However, the board can modify the new policy or stop it.

Hirokawa said the pause also gives county lawyers time to review a 3-week-old federal court ruling from Oregon that found restrictions on incoming and outgoing mail in a suburban Portland-area jail unconstitutional. The ruling noted that the policy “prevents an inmate’s family from sending items such as photographs, children’s report cards and drawings, and copies of bills, doctor reports, and spiritual and religious tracts.” However, the decision is not binding in California. Nationally, the ACLU has won cases in Florida and Colorado, while challenges by inmates and other groups elsewhere have met with mixed results.

Before the community meeting, Hirokawa also will consider tweaking the policy, including allowing inmates and their correspondents to use email, and families to send photos via snail mail.

However, even if email is permitted, there’s a payoff for the system. The Main Jail and Elmwood now get more than 200,000 pieces of mail a year — the vast majority of which is not read by the authorities unless there is a “bona fide reason,” one jail official said. But all email could be closely monitored via search functions that can easily track keywords ranging from gang names to drugs. Software also can translate foreign languages.

The postcard-only trend started in 2007 when Joe Arpaio, the controversial sheriff in Maricopa County, Ariz., banned incoming, nonlegal mail except for postcards, according to the Massachusetts-based Prison Policy Initiative. Nationally, a few dozen out of about 3,000 jails have adopted it. In California, at least four counties have such a policy — San Diego, Santa Barbara, Ventura and Sacramento.

But Los Angeles County rejected the policy out of concern it would aggravate inmates’ mental health problems — and possibly spark violence. No state prison system has taken it up. According to a spokesman for the California prison system, “Letters are a really good rehabilitative tool. It keeps them connected to the community, it’s very important.” But, he noted, the prisons may not need to restrict mail because they have dogs that can sniff out contraband, including cellphones.

One other difference between jails and prisons is that everyone in prison has been convicted of a crime, while two-thirds of the 3,986 inmates in Santa Clara County jails still have pending cases, many of which are misdemeanors. They are considered innocent until proven guilty.

“We’re a civilized society, and we need to treat incarcerated individuals in a civilized way,” Public Defender Molly O’Neal said. “Letters keep them from acting out and give them something to do. It’s a positive in a negative situation.”

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com/tkaplanreport.